This paper seeks to show something more than the role played by the Mexican military during the Second World War (1939-1945), when they participated in the hostilities towards the end of the armed conflict in the Far East. However, the fact, that the southern border of the United States was firmly sealed by Mexico, and the altogether contribution by Mexico with the "army of the braceros" and by thousands of "American mexicans", who gave their lives wearing uniforms of the US armed forces, can not be underestimated.