If you ask people to name the victorious Allied Powers in World War II, Mexico isn’t usually a name that comes to mind. But after declaring war against the Axis in mid-1942, Mexico contributed to the Allied victory in important ways. Despite long standing tensions with the United States, Mexico would become a valuable ally to its northern neighbor, ramping up its industrial production and contributing vital resources to the Allied war effort.

In addition, thousands of Mexican nationals living in the United States registered for military service during World War II. Mexico’s own elite air squadron, known as the Aztec Eagles, flew dozens of missions alongside the U.S. Army Air Force during the liberation of the Philippines in 1945.

On the home front, hundreds of thousands of farm workers crossed the border to work for U.S. agricultural companies as part of the Bracero Program, which outlasted the war by nearly two decades and have a lasting impact on the relations between the two North American nations.

As the first rumblings of another great war stirred in Europe in the 1930s, Mexico and the United States seemed like unlikely allies. In 1938, Mexico’s reformist president, Lázaro Cárdenas, nationalized the country’s oil industry, which angered powerful U.S. oil companies.

“The late 1930s was a time of increasing tensions between Mexico and the United States on the diplomatic front, largely tied to the nationalization of oil,” says Monica Rankin, associate professor of history at University of Texas-Dallas and the author of México, la patria: Propaganda and Production During World War II. Plus, many Mexicans still resented the United States for the loss of 55 percent of Mexico’s territory after the U.S.-Mexican War (known in Mexico as the North American Invasion).

But as the war in Europe began to disrupt trade routes around the world, Mexico and other Latin American countries found themselves in economic peril. “Over those years as World War II is heating up,” Rankin explains, “the United States is slowly stepping in and replacing Europe in places where Latin America really relied on European markets for trade.”

Then came Japan’s surprise attack on Pearl Harbor in December 1941, which brought the war to the Western Hemisphere for the first time. Mexico cut diplomatic ties with Japan on December 9, 1941; it broke with Germany and Italy by December 11. In January 1942, at the Conference of Foreign Ministers held in Rio Janeiro, Brazil, Mexico’s delegation argued forcefully that all the nations of the Western Hemisphere must band together in mutual cooperation and defense.

That May, German U-boats sank two Mexican oil tankers in the Gulf of Mexico. Germany refused to apologize or compensate Mexico, and on June 1, 1942, President Manuel Ávila Camacho issued a formal declaration of war against the Axis Powers. U.S. Secretary of State Cordell Hull celebrated Mexico’s entry into the war on the Allied side as “further evidence that the free nations of the world will never submit to the heel of Axis aggression.”

For the Mexican people, participation in World War II would come to signify a continuation of the spirit that had animated their own revolution. “Over the couple of decades after the [Mexican] Revolution took place, the common narrative became that it ousted a dictator,” Rankin says. “The association of the totalitarian push in Europe with the authoritarianism that the Mexican Revolution overturned is a natural association for people.”

Though the government passed the Compulsory Military Service Law in August 1942, Ávila Camacho made it clear that Mexico’s war participation would be limited to economic and material assistance. But over time, Rankin says, the Mexican president wanted a greater role in wartime strategy (and post-war peace negotiations), and decided military participation would be the best way to achieve this.

The result was Squadron 201, better known as the Aztec Eagles, which left for intensive training in the United States in July 1944. “The squadron is hand-selected by the president and his military advisers,” Rankin says. “The son of one of Mexico's revolutionary heroes is one of the members of the squadron. This is the best, the brightest, the most brave that Mexico has to offer.”

The Aztec Eagles (including 33 pilots and more than 270 support personnel) arrived in Manila Bay in the Philippines on April 30, 1945. Over the next few months, they flew 795 combat sorties and logged almost 2,000 hours of flying time, including conducting bombing missions over Luzon and Formosa and providing support for U.S. airmen. Seven pilots from Squadron 201 died in the conflict; the surviving members returned to a heroes’ welcome in Mexico after Japan’s surrender. The squadron played an important symbolic role, inspiring national and cultural pride among Mexicans at home and helping to keep them invested in the war effort.

Mexico also allowed the U.S. military to register and conscript Mexican nationals living in the United States during the war. According to one estimate, around 15,000 Mexican nationals served in the U.S. military during World War II, many of whom may have been motivated by the offer to apply for U.S. citizenship in return for their service. Of these, some 1,492 are believed to have been killed, imprisoned, injured or disappeared.

In 1942, the U.S. and Mexican governments agreed to recruit more than 300,000 Mexicans to work low-paying agricultural jobs in the United States, many of which had been left empty as Americans went off to war or took on more highly skilled positions in armaments factories.

By the time the Bracero Program (from brazo, the Spanish word for arm) ended in 1964, some 4.6 million labor contracts had been signed, with many braceros returning on multiple contracts to work agricultural jobs in more than 25 states. Despite heated opposition to the Bracero Program from critics in both countries, it would lay the foundation for continued U.S. reliance on migrant laborers from Mexico and other Latin American nations to fill low-paying jobs in agriculture and many other industries.

Perhaps the most important lasting consequence of Mexico’s participation in World War II was the impact it had on the Mexican economy. During the war, Mexico provided more strategic resources to the United States than any other Latin American nation, including vital minerals such as copper, zinc, mercury, cadmium, graphite and lead. To do this, it underwent a period of industrial and economic development during and after the conflict that became known as the “Mexican Miracle.”

With aid from its northern neighbor, Mexico’s national income nearly tripled between 1940 and 1946, and its economy grew at an average rate of 6 percent per year between 1940 and 1970. According to Rankin, the roots of this miraculous growth were grounded firmly in Mexico’s participation in World War II.

“Mexico got a lot of aid from the United States to develop industries that were vital in helping to support the war, and those industries stayed once the war was over,” she says. “There's a lot of infrastructure development and creation of industry that becomes a fundamental part of Mexico's economic growth in the second half of the 20th century that has its roots in World War II.”