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Bolivia’s obscure war with Paraguay showcased the modern weapons and tactics that would become so familiar in the upcoming world war.

From 1932 to 1935 Bolivia and Paraguay were locked in a savage struggle that produced the bloodiest but least-known conventional war in the Americas in the 20th century. Officially, it was a war for an arid waste- land that may have had oil beneath it. In reality, it was a war about national pride and identity. And in that sense and others, it was a harbinger of the world war that engulfed the planet just a few short years later.

The surprisingly modern conflict involved airplanes, tanks, flamethrowers, and motor transport. It featured strategic bombing and the first (and last) cross-border armored assault in the Americas. Russian and French officers advised the smaller Paraguayan army; a German general and other German officers who had served in World War I commanded the Bolivians. As for tactics, the Chaco War offers a study in leadership, both brilliant and utterly disastrous. The Paraguayan commander, José Felix Estigarribia, was one of the best generals ever to command forces in the Americas; the Bolivian commander, Hans Kundt, was one of the worst.

Yet in the end, Germany, the Union of Soviet Socialist Republics, Great Britain, and the United States paid little heed to this, the deadliest South American clash of the last century.

The Chaco War was long in coming. Ever since losing their ocean coast- line to Chile in the War of the Pacific in 1879 –1883, Bolivians had dreamed of acquiring their own port to provide access to the world. With little chance to defeat the Chileans and regain their former territory, the Bolivians looked to the east and the Río Paraguay, which, although far inland, was deep and flowed into the Río de la Plata and finally the Atlantic Ocean. The river ran through the Chaco, an arid and virtually unpopulated region with few natural resources smack in the middle of the South American continent. Its few settlements had been established under Paraguayan authority and most of the Chaco was acknowledged as coming under Paraguayan jurisdiction.

In the first decades of the century, the Paraguayans offered the Bolivians a solution to their lack of ocean access: the use of a port on the Río Paraguay. The Bolivians, however, still smarting after their loss generations earlier, would accept nothing less than total ownership of a port and the region connecting it to Bolivia. To support their entitlement to the Chaco, they dredged up claims from the Spanish colonial era that placed the Chaco under the Viceroyalty of Peru. The Paraguayans based their title to the Chaco on 16th-century Spanish charters issued by the Viceroyalty of Río de la Plata. The argument about who really owned the Chaco simmered for decades, but was brought to a flashpoint by the discovery of oil at the westernmost extremity of the Chaco, near the Bolivian border.

For Bolivia’s leaders, possession of a river port and exploitation of a potential oil boom became an obsession that overrode all common sense. For the Paraguayans, the claim to the Chaco was rooted deeply in their sense of nationhood. Brazil and Argentina had taken a third of Paraguay’s territory in the disastrous War of the Triple Alliance (1864–1870). Losing another huge chunk of territory would have reduced Paraguay to little more than a third of the land that it had held at the time of independence from Spain in 1811 and Paraguay’s very sovereignty as a nation would have been in question.

At the heart of the conflict was an area still unexplored as late as the 1930s. The Gran Chaco, roughly 100,000 square miles in size, was bordered by the unnavigable Río Pilcomayo and Argentina on the south, and by the Río Paraguay and the fertile region of central Paraguay in the east. The Chaco is rimmed by the Andean lowlands of Bolivia in the west, and in the north and northwest by jungle regions of Bolivia and Brazil.

Thick brush and quebracho trees cover the region. Quebracho wood, reputed to be the hardest wood in the world and rich in the tannin used for tanning leather, was one of the few exploitable resources of the Chaco. Clusters of Paraguayan settlers logged quebracho trees and had built several short, narrowgauge railways into the region to haul the logs out. These small logging railroads—particularly the railway that started at Puerto Casado and stretched 100 miles into the Chaco—would assume great strategic importance in the war.

The region had only a few settlements near the few sources of water. For most of the year the Chaco is hot, dry, and home to an impressive variety of poisonous snakes. During the brief rainy season the few roads—dusty tracks for most of the year— are turned into impassable quagmires. By any reckoning, it was a highly inhospitable region in which to fight a war.

Through the 1920s, both nations prepared for a war that both sides considered inevitable. For Paraguay it was brave, even foolhardy, to resist the Bolivian demands. In 1930 Bolivia had a population of three million people to Paraguay’s 900,000. Bolivia was rich in tin, silver, and oil, and its economy was several times larger than Paraguay’s, which was almost completely agricultural and driven by exporting cotton, palm oil, beef, and leather.

As Bolivia and Paraguay built up their armed forces, Bolivia had the deeper coffers. In 1926 it contracted with Vickers, the British armaments firm, to provide hundreds of heavy and light machine guns, more than 100 artillery pieces, vast quantities of ammunition, and even some tanks. Vickers also produced some of the top fighter aircraft of the era, so the Bolivians acquired Vickers Vespa and Type 143 fighters. By 1932 Bolivia had an exceptionally well-armed regular army of 6,000 men backed up by another 30,000 reserves. It had a modern air force of 40 planes including the Vickers fighters and some French bombers. The Bolivians even had a small tank corps equipped with the latest Vickers Carden-Loyd tanks.

The Paraguayans strained their national economy to the limit in the 1920s, attempting to buy enough weapons to oppose the military juggernaut the Bolivians were building. They bought Mauser rifles from Spain, Madsen light machine guns from Denmark, and Browning heavy machine guns from the United States. Since the French sent a large military mission to train the Paraguayans in the 1920s, much of the Paraguayan equipment was acquired from France. In the 1920s the Paraguayans bought 32 75mm and 105mm field pieces from the French Schneider & Co. The Paraguayan air force, about half the size of Bolivia’s, was equipped with French Potez 25A.2 light bombers and Wibault 73C.1 fighters.

But with very limited resources, Paraguayans had to pinch every penny. So the Paraguayan army kept its artillery procurement small and instead bought 81mm Stokes mortars, which were cheap. Paraguay’s small industrial sector could easily manufacture the mortar ammunition.

Although inferior in armaments, the Paraguayans worked much harder to prepare their army for the coming clash than did the Bolivian army’s garrison force. The syllabus of the Paraguayan officer academy was overhauled, with emphasis on studying the lessons of World War I. An NCO academy was created to ensure competent lower-level leadership. By 1931 Paraguay had 4,000 regular soldiers under arms and was ready to mobilize 16,000 more.

The dominant military figure in Bolivia in the two decades before the Chaco War was a German officer, Hans Kundt. Kundt was commissioned in 1888 and served on the Prussian General Staff before coming to Bolivia in 1911 as the chief of a German military training mission.

He fell in love with the country and developed a reputation among the Bolivians as a superb administrator. Recalled to Germany at the outbreak of World War I, Kundt served on the eastern front as a brigade commander and corps chief of staff, and retired from the German army after the war as a major general.

His adopted country then invited Kundt back, offering him the position of army chief of staff and war minister with the rank of full general. Kundt eagerly accepted the post and directed Bolivia’s rearmament program in the 1920s as he prepared to occupy the Chaco.

Kundt was an imposing man with a gruff manner. He was also a competent trainer who was concerned with the well-being of his soldiers. His weaknesses, however, outnumbered his strengths. During World War I, he had earned a reputation as a thoroughly mediocre tactician, preferring frontal assaults in most combat situations. He considered himself something of a military genius compared with the Bolivian officers, whose advice he routinely ignored. Rather than trust his Bolivian officers, he preferred to micromanage the army.

Despite his general staff background, he had little interest in strategy. Although most Bolivian leaders believed that a war in the Chaco was inevitable, Kundt never visited the region or made any attempt to study the terrain. He concluded that a war with Paraguay would be an unopposed march into the region and peaceful occupation—so what need was there to plan?

In fact, as the war began Kundt was in exile for supporting a coup attempt by one of the Bolivian factions. But such was his popularity that he was called back when the war took a turn for the worse for the Bolivians.

Paraguay’s military commander was a dramatic contrast to Kundt. José Felix Estigarribia, who commanded Paraguay’s forces in the Chaco in 1932, was 19 years younger than Kundt. He came from a modest farm family and had studied agriculture. But upon graduation he changed his career ambitions and joined the army as a lieutenant of infantry. Clearly intelligent, he was groomed for rapid advancement and sent to study at the Chilean military academy, then regarded as the best military school in South America.

A diminutive, quiet man, Estigarribia had a reputation as a serious student of modern warfare. From 1924 to 1927 he studied at the French army’s war college, L’École Supérieure de Guerre, in Paris. In 1928 he was appointed as chief of staff of Paraguay’s army but was soon dismissed when he disagreed with the government’s strategy to defend the Chaco. Yet as war looked increasingly inevitable, the government decided it needed Estigarribia and appointed him commander in the Chaco in 1931. Characteristically, he then did something the Bolivians had not done: he traveled throughout the region and carefully studied the terrain.

By June 1932, Bolivia had 6,000 troops in the Chaco, most of its regular army. The I Army Corps with 4,000 Bolivian soldiers was stationed in the southwestern part of the Chaco, and an- other 2,000 troops were organized into two di- visions in the northeast of the Chaco. Although the Bolivian government had not clearly decided upon war, Col. Enrique Peñaranda, commander of the Bolivian forces in the Chaco, decided to force the issue by seizing key terrain as the first step of a systematic takeover of the whole region.

In June a Bolivian detachment took over a small Paraguayan outpost on Lake Pitiantuta. The next month Paraguayan troops retook the post after a small skirmish. The Bolivians then countered by attacking and taking the villages of Corrales and Toledo on July 27 and 28. Three Bolivian regiments, supported by fighter and bomber aircraft, then attacked the Paraguayan fort at Boquerón, which fell at the end of July after heavy fighting.

What had begun as a series of nearly bloodless skirmishes escalated into a full-scale war. Forced into action by Colonel Peñaranda’s offensive, the Bolivian government bowed to the inevitable and mobilized its reserves, sending another 6,000 reinforcements to the Chaco. General Kundt was still in exile at the time and would take no part in the first four months of the burgeoning war.

The Paraguayans countered the Bolivian offensive by mobilizing their regulars and reserves and deploying an army corps of 8,000 men to the settlement of Isla Poí. A further 1,500 men organized defensive positions at Nanawa in the southeast Chaco. The Paraguayan 3rd Division, with 3,000 men and eight field pieces, moved into position on the upper Río Paraguay. In August a further 3,000 reinforcements were dispatched from Asunción.

The Bolivian strategy, if one could call it that, had blithely assumed that Paraguay would not fight for the Chaco; their forces outnumbered the Paraguayans and were far better equipped. So the Bolivian plan simply called for an unopposed advance of Bolivian arms to the Río Paraguay. When this assumption proved false, the Bolivians were confronted with a serious strategic problem: a long and tenuous supply line running back to their main base in Bolivia.

Troops were mobilized in the mountain heartland of Bolivia and transported by train most of the way to the main Bolivian base, the city of Villa Montes in the Bolivian lowlands. Horses, traditionally the main transportation of both the Bolivian and Paraguayan armies, played almost no role in this war, as they quickly sickened and died from the heat of the Chaco and the lack of fodder. Both armies learned that motor vehicles were the only reliable way of moving through the region. But the Bolivians only had enough trucks to get their most vital supplies forward; there was no space in them to carry soldiers.

So the Bolivian infantrymen marched from Villa Montes 200 to 300 miles through the choking dust and heat of the arid wilderness to get to the front. The Bolivians, used to a cool mountain climate, suffered terribly on the weekslong march and were often exhausted and sick when they arrived in the battle zone.

While Paraguay was at a significant disadvantage in troop numbers and armament, its logistics were much more favorable. Like the Bolivians, the Paraguayans suffered from a shortage of trucks, but they had river and rail transportation available, so their relative dearth of trucks had little impact. The Para guayans could move troops from the capital of Asunción by steamer up the Río Paraguay to the river port at Puerto Casado and from there take the narrow-gauge railroad, built to haul quebracho logs, into the Chaco. The Paraguayans had built their main base at Isla Poí, which lay only 18 miles from the end of the train line; unlike the Bolivians, the Paraguayan reinforcements arrived at the front fresh and rested.

At the start of September, Estigarribia was ready to carry out his battle plan. He concentrated his I Corps and sent it to cut off and then seize the thousand-man Bolivian garrison at Boquerón. When the first Paraguayan attack on September 9 failed, Estigarribia laid siege to the garrison. Then the Paraguayans quietly infiltrated forces deep into the Chaco to interdict any attempts to relieve the garrison at Boquerón. Soon after the initial Paraguayan attack, a whole column of trucks bearing the Bolivian 13th Infantry Regiment sent to relieve Boquerón fell into a trap and was shot to pieces. There would be no relief for the embattled Bolivians.

Although the Bolivians had far more equipment and troops, the Paraguayans proved to be quick learners and they developed a host of tricks to counter Bolivia’s advantages. For example, Bolivia had the better air force and held air superiority throughout the war. The Bolivians’ capacity to put re con naissance aircraft all over the front ought to have given them a decisive advantage. But the Paraguayans became masters of camouflage. To surprise the Bolivians, the Paraguayan engineers built their roads and trails through the thick brush of the Chaco. The Paraguayans didn’t make their trails straight, choosing routes that allowed them to weave higher branches of nearby trees together, shielding the trails from aerial reconnaissance. The Paraguayan camouflage was so effective that many of their large troop movements went unnoticed.

Meanwhile, at Boquerón the situation worsened for the Bolivian defenders. To keep the garrison supplied, the Bolivian air force dropped ammunition, food, medical supplies, and water into the fort. The Paraguayans countered by ringing Boquerón with heavy machine guns. Ground fire forced the Bolivian aircraft to drop their supplies from high altitude—and most of them were blown into the Paraguayan lines.

The Bolivian high command had no idea that the resupply effort had failed and that their soldiers at Boquerón were in desperate straits, with little water, food, or ammunition. They were completely surprised when the Boquerón garrison surrendered on September 29. This defeat at the hands of the outnumbered and poorly equipped Paraguayans gave the Bolivian high command and political leaders a shock from which they would not quickly recover. Conversely, the victory gave a huge boost to Paraguayan morale, demonstrating that they could defeat a superior enemy with good leadership and tactics.

After Boquerón, both sides needed to rest and reorganize. The Bolivians reinforced their army in the Chaco and recalled General Kundt from exile in Berlin to be commander in chief of their forces. There was public rejoicing in La Paz when the decision was announced. Bolivia’s most popular military figure was expected to pull the army together and quickly defeat the Paraguayans. After all, how could Paraguay counter a man who had fought in the Great War in Europe?

Upon his triumphal return to La Paz in December 1932, Kundt issued orders for a major offensive in the southern part of the Chaco. Kundt and the Bolivian leaders believed that if they occupied the southern part of the Chaco, they would threaten the enemy capital at Asunción and Paraguay would soon capitulate.

In December 1932, the Bolivian 8th Division launched an attack, driving the Paraguayan forward lines back to just south of a road junction known as Kilometer 7. The strategic point for the control of the southern Chaco was a small fortified settlement at Nanawa. Kundt predicted that one grand thrust to break the Paraguayan forces and take Nanawa would decide the war. Detailed plans were issued for a Bolivian attack to take place in January 1933.

With their much smaller army and paucity of artillery and airplanes, the Paraguayans were at a clear disadvantage. But Estigarribia had two secret weapons. The first was the outstanding Paraguayan intelligence service. The Paraguayans had some very good spies in La Paz and the Bolivians had been careless about guarding their war plans. Estigarribia soon knew all the details of the Bolivian offensive. Indeed, throughout the war the Para guayans were very well informed about their enemies’ intentions.

Paraguay’s other secret weapon was a group of former Russian imperial officers that had settled in Paraguay in the early 1920s after being forced into exile from their homeland. The most notable of the more than 40 White Russians who volunteered to serve their new country was Gen. Ivan Beliaev, who had settled in Paraguay in 1923 and had taught engineering at the Paraguayan military academy.

Beliaev and other former czarist officers designed a series of connecting fortifications around the settlement of Nanawa. In the heart of South America, they created a defense system equal to anything seen in World War I. The core of the Paraguayan defense was a series of earthwork strongpoints, each with artillery and machine guns protected by bunkers built of logs and topped with layers of earth. The strongpoints were carefully camouflaged and sited for interlocking fire, and mines were laid on the most practical approaches.

In January 1933, Kundt unleashed a series of attacks against these Paraguayan defenses. Kundt was convinced that his plan was a masterstroke. “We will finish the war in three months,” he announced to his officers, “and all of you will soon be in La Paz, and I will return to Berlin where, in April, I have an engagement to attend to.”

But Kundt’s frontal assault tactics were no more successful than similar attacks on entrenched positions in the world war, and the Bolivian attack fell to pieces under Paraguayan machine gun fire.

Facing his German adversary for the first time, Estigarribia coolly responded to every Bolivian move. When heavy rains made the roads to Nanawa impassible and some of the Paraguayan units ran short of ammunition, Estigarribia mobilized his modest air assets—bombers, fighters, and transports— to fly ammunition into a rough airstrip at Nanawa. The improvised airlift allowed the Paraguayans to hold their positions. By early February it was clear even to Kundt that his assault had failed. The conflict settled into a period of frustrating static warfare.

In the meantime, Kundt began preparations for an even grander offensive. This time Bolivia would break the Paraguayan army at Nanawa by employing all of its advantages in weaponry. First, the attack would be preceded by a massive artillery barrage. Then, the Bolivian air force would find and destroy the Paraguayan artillery. To neutralize machine guns, the Bolivians would send in tanks, accompanied by teams with flamethrowers. Kundt expected the Paraguayans to be overawed and quail before the Bolivian weapons.

By late June 1933 most of the Bolivian army was in position for a frontal assault on the Paraguayan positions at Nanawa. On July 4, the Bolivians began to move forward under the cover of a massive artillery barrage.

But the Paraguayan positions had been substantially strengthened since the battles earlier in the year, and Bolivian artillery failed to do much damage to the Para guayan bunkers. The Para – guayan guns and mortars had been well camouflaged, and the Bolivian air force was unable to find and destroy them.

Now Paraguay’s reliance upon the simple and inexpensive 81mm Stokes mortars instead of heavy artillery, a choice forced upon them by their poverty, proved to be an advantage. In the Nanawa campaign, the Stokes mortars were more effective and lethal in the heavy brush of the Chaco than the Bolivians’ heavy guns. As in January, the Bolivian attack soon bogged down under the Paraguayan machine gun and mortar fire.

To keep up the momentum of the attack, Kundt unleashed his small tank force to break open the Paraguayan defenses. But Estigarribia’s spies had told him about the Bolivian armor, and the Paraguayan commander had placed some of his 75mm guns in the front line to serve as antitank guns. He had also issued the Paraguayan machine gunners armor-piercing ammunition. Although it could not penetrate the main tank armor, it could pierce the lightly armored engine compartments and disable the tanks.

The thick brush of the Chaco, which allowed little visibility, also made for poor tank country. Two Vickers heavy tanks soon broke down and another was knocked out by a direct hit from a carefully hidden 75mm gun. The heavy tanks were repaired and sent back in. Then the Paraguayans concentrated their armor-piercing machine gun fire on the Vickers’ view slits. With nearly every crewman wounded, the tanks soon retreated. George Landen, a British army officer observing the Bolivians, laconically noted that they “relied to a great extent on their modern arms…and have been somewhat disillusioned.”

Frustrated by the strong resistance, Kundt remained true to form and simply ordered more frontal assaults. Nanawa surely won its reputation as the Verdun of the Chaco. For the next two days the Bolivians threw wave after wave of attackers at the Paraguayan strongpoints. They made some small gains but the main strongpoint held firm. After three days of intensive battle, more than 2,000 Bolivians had been killed, while the Paraguayans had lost only 149 dead and 400 wounded.

Faced with another failure at Nanawa, Kundt directed his forces to carry out a series of attacks at Toledo, now back in Paraguayan hands. There again the Bolivians faced tough defensive positions designed by the White Russian officers and the Bolivian frontal attacks were again repulsed—with heavy losses.

After Nanawa, both forces did some repositioning and a series of small battles ensued. Surprisingly, Kundt remained optimistic. “Actually there exists no possibility of defeat,” Kundt declared to the Bolivian cabinet. “The recent reverses…have been exaggerated.”

While Estigarribia had proven successful at defensive warfare, he constantly looked for a means to take the offensive against the Bolivians. Since he had been outgunned and outnumbered throughout the war, he would have to pick the moment and plan carefully to exploit any Bolivian weaknesses. Luckily for him, in addition to his White Russian officers, Estigarribia also had some first-rate senior Paraguayan commanders who aggressively carried out his plans.

The best of Estigarribia’s subordinates was Rafael Franco, who had been dismissed from the army before the war for political reasons. At the start of the war he was recalled to the army, promoted to major, and given command of a regiment. By the summer of 1933, he was a colonel in command of the 1st Division.

Franco’s long-range patrols found some gaps in the Bolivian lines at Alihuatá and on July 12, he launched a surprise attack that quickly penetrated enemy lines and cut the Bolivian 4th Division to pieces, forcing it into headlong retreat.

The Bolivian government continued to have faith in the prowess of its German general, but the Bolivian commanders at the front now had grave doubts. His handling of the battle at Nanawa (and the losses at Alihuatá) had left the Bolivian forces demoralized. There was no question of the valor of the Bolivian infantrymen who stormed into the attack, again and again. But they did so only to be slaughtered, and even their superior weaponry had not turned the battle in Bolivia’s favor. The problem, clearly, was at the top.

Col. Bernardino Bilbao Rioja, commander of the Bolivian air force, summed up the view of many senior officers: “Kundt might have been an adequate lieutenant, but he lacked all the qualities necessary for commanding large units in combat.”

At this point in the war, a full mobilization and the employment of Bolivia’s superior wealth and manpower might have overwhelmed the hard-pressed Paraguayans. But Kundt, trying to curry favor with the government, minimized the setbacks and he refused to call for more troops and equipment.

The Paraguayans had been counting on Kundt to stay in character, and they were not disappointed. In the 1920s Estigarribia and his staff had made a careful study of their most likely opponent. When Kundt’s return was announced, Estigarribia offered his assessment of the German at a staff conference, saying that Bolivia’s top commander was “self-confident and tenacious” and his style of command “left no room for his subordinates to exercise their initiative.” Estigarribia noted that Kundt’s record in World War I showed “he was a fervent devotee of the offensive at all costs.”

The Paraguayans now saw a chance to use another of Kundt’s flaws to their advantage. He was known to order his commanders to never yield ground. This meant that if the Paraguayans could cut off a part of the Bolivian force, Kundt would not likely allow them the chance to retreat and save themselves.

Estigarribia now looked to return to the offensive. Colonel Franco’s defeat of the Bolivian 4th Division was a good start. Estigarribia, like his opponent, believed that too much time spent on the defensive was “bad for the soldier’s fighting spirit.” But Estigarribia had also learned from his opponent that frontal assaults did not work either, so he waited for a chance to outflank and cut off a large part of the Bolivian force. In December 1933, his opportunity came.

A month earlier, after several weeks of skirmishing, Para – guayan air and ground patrols spotted some large gaps in the Bolivian lines near Campo Via in the Central Chaco. For two weeks Estigarribia quietly concentrated his forces. On December 3 the Paraguayans unleashed an attack through one of the gaps in the Bolivian front his patrols had found.

The attack was a complete surprise and in short order the Bolivian 4th and 9th divisions were caught in a classic double envelopment. General Kundt reacted slowly to the developing crisis. When the Paraguayans began their attack, Bolivian reconnaissance pilots brought several reports that accurately identified the Paraguayan strength and unit movements. But Kundt had a low opinion of airmen and rejected these reports, calling them “alarmist.”

Some of the Bolivian unit commanders also saw the danger from the Paraguayan offensive and requested permission to shorten their lines, which were overextended and now vulnerable. Kundt rejected the idea that the Paraguayans could operate on a broad front and strike deep enough to surround his divisions. Convinced that the Paraguayan offensive was nothing more than a raid, Kundt strictly forbade his commanders to cede any ground and all but accused his senior officers of cowardice for even suggesting that the Bolivian forces pull back in threatened sectors. Thanks to him, what might have been a limited Bolivian defeat turned into a national catastrophe.

Estigarribia knew that he could rely on the aggressive Colonel Franco to effectively carry out a key maneuver of the battle. On December 7, Franco initiated an attack that again took the Bolivians by surprise. His division quickly pushed ahead to cut the main Bolivian supply lines. Only when the Paraguayans had closed the trap and cut off two Bolivian divisions did Kundt try to salvage the situation.

On December 10, the Bolivians finally tried to break through to the trapped corps, but their counterattack was badly coordinated. Bolivian air units, supporting their ground forces, were so poorly informed of the attack plans that they dropped as many bombs on their own troops as on the Paraguayans. The final, desperate attempt to save the surrounded soldiers failed, and on December 11 the two Bolivian divisions surrendered. This was Bolivia’s greatest disaster of the war. More than 2,600 Bolivian soldiers had been killed, and another 7,500 were taken prisoner. At one stroke, a major part of Bolivia’s frontline forces was destroyed. Only 1,500 men had escaped from the pocket.

As the Bolivian army fled in headlong retreat, President Daniel Salamanca finally removed Kundt as commander in chief. He promoted Col. Enrique Peñaranda, whose actions had precipitated the war, to brigadier general and made him commander in the Chaco.

For the Paraguayans, the victory at Campo Via turned the war around. In addition to thousands of prisoners, they captured 8,000 rifles, 536 machine guns, 25 mortars, and 20 artillery pieces, a large quantity of ammunition, and dozens of motor vehicles.

The war booty was a godsend for a poor nation like Paraguay, which now could replace much of its lost and worn-out equipment, and could even equip new units being sent to the front. With this bounty, Estigarribia could maintain an offensive.

But Paraguay’s president, Eusebio Ayala, ordered Estigarribia to stop pursuing the beaten Bolivians. Ayala was convinced that the victory at Campo Via had broken Bolivia’s will and that the time for a negotiated settlement had come. Against Estigarribia’s advice, Ayala ordered a truce.

Once the Paraguayans stopped their pursuit of the retreating Bolivians, however, the Bolivian cabinet regained its nerve. Despite the disaster, Bolivia could still field more men and guns than Paraguay. Now that Kundt had left, some of the senior Bolivian officers figured they could still win the war. Both sides used the truce to reorganize their forces and bring up supplies. After a few weeks, the fighting resumed.

The Paraguayans faced increasingly long logistics lines as they slowly drove the Bolivians back. Finally, the Bolivians managed to piece together a sound defensive line. In May 1934 Col. Bernardino Bilbao Rioja, the former air force chief who now assumed command of a corps, prepared a trap for the advancing Paraguayan 8th Division. Near the settlement of Cañada Strongest, the Bolivians caught the Paraguayan division in a surprise flank attack and surrounded it.

Although the Paraguayans were taken by surprise, Estigarribia reacted swiftly, ordering his forces to fight their way out. Most of the 8th Division broke out of the trap in good order, but the Paraguayans lost 500 dead and 1,500 prisoners in the process. It was Bolivia’s greatest victory of the war and Bilbao Rioja, who had long been ignored and disparaged by Kundt, had proven himself to be Bolivia’s best field commander.

After that setback the Paraguayans continued their advance, albeit more cautiously. In July the Paraguayan offensive was stopped at Picuiba. Still, Estigarribia looked for a way to keep the initiative and maneuver his troops to gain an advantage. He finally found his chance at El Carmen in November 1934 when his surprise flank attacks surrounded the Bolivian reserve corps. Such carefully prepared envelopment operations—ironically, the province of such Prussian-trained commanders as Kundt— had become Estigarribia’s trademark, and this time it worked to perfection. Two thousand Bolivian troops were killed and 4,000 prisoners were taken. Only 2,000 Bolivian troops fought their way out of the pocket to safety.

The El Carmen disaster created a fresh crisis for the Bolivian government. President Salamanca was furious at the incompetence of senior commanders who had allowed their materially and numerically stronger force to suffer such defeats. Of his officers he said, “I have given them everything they asked for. But I could not give them brains.”

A group of senior officers led by Gen. Enrique Peñaranda, believing that they might be relieved of command, struck preemptively and mobilized the La Paz garrison as they confronted the president. They forced Salamanca to resign the presidency in a quiet coup. On his way out, Salamanca facetiously congratulated his top general, pointing out that the operation to remove him had been Peñaranda’s only successful military operation to date.

Estigarribia’s victory at El Carmen allowed him to pursue the Bolivians, and by early 1935 the Bolivian army had fallen back inside the Bolivian border to its base at Villa Montes, near the Andean foothills. Col. Bilbao Rioja was put in charge of organizing the defense of Villa Montes, the vital logistics center of the Bolivian army.

The Paraguayans crossed the Río Parapiti in April 1935 but in a series of savage counterattacks, the Bolivians threw the Paraguayans back across the river. Bilbao Rioja had again saved the Bolivian army from disaster.

By this point Bolivia had given up on any idea that it could conquer the Chaco by force. For their part, the Paraguayan troops were stretched to their limit. Both sides were suffering from attrition and exhaustion and a negotiated settlement was the only sensible solution.

On June 14, 1935, exactly three years after the war began, Generals Peñaranda and Estigarribia signed an armistice ending the war. Subsequent negotiations recognized Paraguay’s claim to virtually all of the Chaco, although in a compromise, Bolivia gained a corridor to the Río Paraguay and a port.

The casualty numbers give an idea of the true scale of the conflict. Bolivia, with three million people, mobilized 210,000 men. Of these approximately 60,000 were killed, and 23,250 were taken prisoner. Paraguay, with a population of 900,000, mobilized 150,000 men, lost 31,500 dead and missing, and another 2,500 taken prisoner. In comparing these losses to the total population, only a few nations at war in the 20th century suffered a higher percentage of loss.

The Chaco War was, in many respects, a very modern war. Late-model tanks had been used, both sides had relied primarily upon motor transportation, and close air support was a major feature in many battles. Both sides even set up extremely efficient systems to evacuate their wounded and sick from the front lines by air, thereby saving the lives of thousands of soldiers.

Yet, surprisingly, this war that featured modern weapons and large-scale maneuvers was hardly noticed by the major powers. Assuming that there was nothing to be learned from small South American countries, none of the major powers—Germany, the United States, Great Britain, Japan—sent official observers. American staff colleges and military journals ignored the war completely. In Europe and even the United States, press coverage of the Chaco War was minimal and the few stories that came out were sensationalized and inaccurate.

Sadly, the Western powers missed an opportunity to learn some useful lessons for the world war soon to come. They might have learned, for instance, that superior equipment and resources do not guarantee victory.

Throughout the Chaco War the Paraguayans were outgunned and outnumbered, often by a factor of two to one. Yet the Paraguayans still managed to win most of the battles. The keys to victory lay in better training, better tactics, better planning, and, most of all, superior leadership at all levels. Despite Bolivia’s superior forces, the Paraguayans had the better leaders in commanders such as Estigarribia, Franco, and Beliaev— and that, in the end, spelled victory for Paraguay.


Originally published in the Summer 2009 issue of Military History Quarterly. To subscribe, click here.