During World War I, Brazil sent observers to the French army. Subsequently, Brazil requested a French military mission to modernize the Brazilian army based on French models. The mission ended in 1939 with the outbreak of World War II.
During the interwar period, Brazil shifted its economic policy toward both the United States and Germany. Getulio Vargas came to power in 1929 with the support of the army. As a dictator, Vargas sympathized with Germany's economic issues, and he quadrupled trade between Brazil and the new Nazi regime during the 1930s.
When war broke out, Brazil was torn between its traditional economic ties with the United States and its new friend, Nazi Germany.
Brazil Heading Towards War
Following the Axis' initial victories in France and North Africa, as well as the potential defeat of England in Europe, Brazil's geographical location became strategically important to the United States. On June 25, 1940, the US Naval and Air Missions to Brazil initiated negotiations with the Brazilian government. The negotiations aimed to establish American naval and air bases in northeastern Brazil, allow American soldiers to pass through Brazilian territory, and supply America with raw materials Brazil produced in large quantities.
In May 1941, the United States granted Brazil an initial loan to purchase war materials. This led to an October 1941 agreement that included Brazil in the American "Lend-Lease" law. Following the Japanese attack on Pearl Harbor on December 7, 1941, Germany declared war on the United States.
At the Rio Conference in January 1942, Brazil broke off diplomatic relations with the Axis, after which the Germans began attacking Brazilian merchant ships along the Brazilian coast. Together with the previous agreements established with the United States, this definitively shifted Brazil to the Allied camp.
Between February and March 1942, Minister Souza Costa finalized a series of military and economic agreements during his mission to the United States.
These agreements permitted the deployment of Brazilian troops in overseas military operations. In return, the United States promised Brazil naval support for defending its coastline and aid for arming and equipping the Força Expedicionária Brasileira (F.E.B.) through a second "Lend-Lease" agreement.
As a result, the United States transferred $200 million worth of weapons and ammunition to Brazil. In return, Brazil agreed to construct barracks, lodgings, and large underground warehouses in the northeast; extend the runway at Fernando de Noronha Airport; and fly without the usual authorizations, but within a predetermined corridor.
Brazil declared war in August 1942.
The establishment of the Brazilian Expeditionary Force
The regional regiments were equipped with German small arms and French artillery whose calibers were completely different from those used by the Allies.
The Brazilian army had been trained according to the French doctrine of "positional warfare," which dated back to World War I. Therefore, it had to be completely reorganized and retrained according to the model of an American division, including the infantry and rear logistics, as well as postal and banking services.
Mobilization began in 1943 with the initial goal of fielding three infantry divisions.
However, difficulties with recruitment, training, and equipment, as well as a lack of sea transport, resulted in the F.E.B. consisting of only one infantry division, the 1st Expeditionary Infantry Division (1st DIE), divisional organizations (OND), and the FAB (Brazilian Air Force — 1st Fighter Group). In total, this amounted to a combat force of 25,334 men under the command of General Mascarenhas de Moraes.
Although small by most Allied standards, this represented a significant effort by Brazil.