Brazil officially entered World War II on August 22, 1942, when it declared war against the Axis powers, including Germany and Italy. On February 8, 1943, Brazil formally joined the Allies upon signing the Declaration by United Nations. Although considered a secondary Allied power, Brazil was the largest contributor from South America, providing essential natural resources, hosting strategic air and naval bases, participating in the Battle of the Atlantic, and deploying the Brazilian Expeditionary Force (FEB) to the Italian Campaign, the only South American country to send combat troops overseas.

Leading up to the outbreak of World War II in 1939, Brazil adhered to a policy of strict neutrality and maintained positive commercial and diplomatic relations with both Allied and Axis powers. Despite Brazil's traditionally strong ties with the United States, by 1940 the country had become Germany's leading export market outside Europe and its ninth largest trading partner. Brazil hosted significant and influential German, Italian, and Japanese diaspora communities, and Brazilian President Getúlio Vargas, whose administration was ideologically sympathetic to fascism, initially aimed to profit from the war by securing favorable trade agreements from both sides.

Brazil's foreign policy progressed through three different phases. Brazil used its relative freedom in the first phase (1935–1940) to play Germany and the United States against one another. As the conflict progressed, Brazil's trade with the Axis powers led to increased diplomatic and economic pressure from the Allies. Following the entry of the United States into the war in December 1941, the Joint Brazil–U.S. Defense Commission was established to strengthen bilateral military ties and minimize Axis influence.

In exchange for direct economic assistance from the United States, Brazil severed diplomatic relations with Germany, Japan, and Italy in January 1942, and allowed the establishment of U.S. air bases on Brazilian soil to counter Axis naval activities,"Avalon Project – A Decade of American Foreign Policy 1941–1949 – Havana Meeting of Ministers of Foreign Affairs of the American Republics, July 21–30, 1940". Avalon.law.yale.edu. Retrieved 2016-09-10 which provoked immediate reprisals from the Axis powers. By mid-August 1942, 36 Brazilian merchant ships had been sunk, with the loss of nearly 2,000 seafarers and passengers, prompting Brazil to declare war.McCann, Frank D. (January 1, 1995). "Brazil and World War II The Forgotten Ally. What did you do in the war, Zé Carioca". Estudios Interdisciplinarios de América Latina y el Caribe. 6 (2). .

Although Brazil's economy and military were relatively underdeveloped, the country committed significant industrial capacity and some armed forces to the war effort. From mid-1942 until the conclusion of World War II, the Brazilian Navy and Air Force actively contributed to protecting Allied shipping from bases in Brazil's northeast region.

Between September 1944 and May 1945, Brazil deployed 25,700 troops to the Italian front. In the conflict, Brazil lost 1,889 soldiers and sailors, 31 merchant ships, three warships, and 22 fighter aircraft. Brazil's participation in the war enhanced its global prestige and marked its emergence as a significant international power.

Overview Brazil's maritime losses were a significant factor in its decision to declare war on Germany and Italy. The country's traditional isolationist stance naturally positioned it against "disturbers of the international order and trade." Public sentiment and government actions culminated in Brazil's declaration of war on Nazi Germany and Fascist Italy in August 1942. That same year, US incentives and diplomatic pressure led to the establishment of airbases along the northeastern coast of Brazil.

At the time, Brazil's population was predominantly rural and faced high levels of illiteracy, with an economy centered on commodity exports. The country lacked the industrial, medical, and educational infrastructure necessary to fully support the war effort. The FEB, which was planned following the Potenji River Conference and the Casablanca Conference, was not formally established until a year after the declaration of war.

Deployment The FEB was deployed to the front in July 1944, nearly two years after Brazil's declaration of war, and was integrated into the Allied 15th Army Group. Of the 100,000 troops originally planned, about 25,000 were sent to Italy. Upon arrival, the FEB, trained and equipped by US forces, carried out the primary missions assigned by the Allied command.

Pre-involvement Predecessors

In February 1942, German and Italian submarines began targeting Brazilian ships in the Atlantic Ocean. This was influenced by Brazil's adherence to the Atlantic Charter, which mandated automatic alignment with any nation in the Americas attacked by a foreign power.

Brazil's gradual alignment with the United States was significant for its government, especially in light of German and Italian attempts to interfere in Brazilian internal affairs. The implementation of the Estado Novo made it increasingly difficult to maintain stable trade relations with these countries, particularly due to British and later US naval pressure. An element of this pressure was President Franklin D. Roosevelt's Good Neighbor policy, which included economic and commercial incentives such as financing the construction of the Companhia Siderúrgica Nacional (CSN).. Reports at the time stated that the United States had planned to invade the northeast of Brazil (Plan Rubber) if Getúlio Vargas insisted on maintaining Brazil's neutrality.

As a consequence of Brazil's entry into the war, the government created to intern Italians, Japanese, and Germans suspected of posing a risk to national security.Duarte, Alexandre. Garattoni, Bruno.

In 1942, following the US proposal to finance the CSN, US forces established airbases along Brazil's North-Northeast coast. The most notable of these was at Natal, near Parnamirim, in the state of Rio Grande do Norte, known as the "Trampoline of Victory" ("Trampolim da Vitória" in Portuguese). This base played a crucial role in the Allied war effort, particularly before the Allied landing in North Africa in November 1942 in Operation Torch. With the stabilization of the Italian front and the diminishing German submarine threat by late 1943, the US bases in Brazil were gradually deactivated in 1944 and 1945. However, the US maintained a presence on Fernando de Noronha until 1960.

Brazilian ships sunk Attacks by Axis submarines on Brazilian ships between 1941 and 1944 resulted in the deaths of over a thousand individuals and were a key factor in Brazil's entry into World War II. Until that point, Brazil had maintained a neutral stance. In this period, thirty-five Brazilian ships were targeted, with thirty-two being sunk.There is no consensus as to the exact number of ships attacked. Some sources include certain events and rule out others. For example, the website "Poder Naval" lists 38 ships. The sinking of Taubaté and Shangri-lá are not included. However, it mentions the sinking of two unidentified ships, one in June 1942, by U-159, and another in August 1942, by , as well as the sinking of White Swan, whose torpedoing was not officially confirmed, as well as the corvette Camaquã and the , which sank for reasons other than acts of war. The World War II portal mentions 39 events, including Shangri-lá, two unidentified ships, the corvette Camaquã, and Bahia, leaving out Taubaté. In some sources, Commander Lira is also not mentioned, likely because the ship was not sunk. Roberto Sander, in his book O Brasil na mira de Hitler lists 34 ships, leaving out Paracuri. The frequency of attacks increased markedly after Brazil severed diplomatic relations with the Axis powers on January 28, 1942. The situation escalated dramatically in August 1942, when six ships were sunk within just two days, causing over 600 casualties. This surge in attacks prompted Brazil to officially declare war on the Axis on August 22, 1942.

In 1943, despite significant enhancements in patrolling and anti-submarine warfare measures through joint Brazilian and US operations, Axis submarines continued their assaults in the South Atlantic, particularly off the coasts of São Paulo and Rio de Janeiro. The majority of the targeted vessels were merchant or mixed cargo and passenger ships, primarily belonging to major shipping companies such as Lloyd Brasileiro, Lloyd Nacional, and Costeira.In September 1942, the private companies Cia. de Navegação Costeira and Lloyd Nacional - both owned by the same owner - were taken over by the government and incorporated into the assets of the state-owned Lloyd Brasileiro. Smaller shipping companies and regional shipowners were also affected,They were: Cia. Carbonífera Sul-Riogandense; Cia. de Cabotagem de Pernambuco and Cia. Serras de Navegação. as well as vessels owned by regional shipowners and seafarers, including the barge Jacira and the fishing boat Shangri-lá. Lloyd Brasileiro, the largest of these companies, suffered the greatest losses, with 21 of its ships attacked, and 19 sunk.

The Brazilian Navy lost three warships in World War II: Vital de Oliveira: An auxiliary ship torpedoed by U-861 on July 19, 1944, while en route to Rio de Janeiro after stops in the Northeast and Espírito Santo. It was the last Brazilian ship to be torpedoed in the war; Camaquã: A corvette that capsized in a storm on July 21, 1944, resulting in the deaths of 23 crew members; Bahia: A cruiser that sank on July 4, 1945, after accidentally detonating its own depth charges in gunnery practice, with 333 casualties;

Also, the ships and Shangri-lá did not survive the conflict.

"Atlantic Belt" The "Atlantic Belt", the narrowest stretch between South America and Africa, was fortified to disrupt the flow of raw materials to the Axis powers, particularly along the 1,700-mile route from Natal to Dakar. This strategic corridor was referred to by the Allies as the "Northeast Ridge". To secure this area, the Allies began establishing bases in Brazil in mid-June 1941. Task Force No. 3 arrived, and the ports of Recife and Salvador were prepared for use by the US Navy. In response, the Axis powers sought to obstruct the shipment of raw materials to the United States and the United Kingdom, leading to attacks on merchant ships navigating the Atlantic.

Pre-entry attacks Beginning of hostilities

On March 22, 1941, the Brazilian merchant ship Taubaté was attacked by a German aircraft in the Mediterranean, off the coast of Egypt. This incurred Brazil's first wartime casualty, with gate clerk José Francisco Fraga being killed.. On June 13, 1942, a German submarine intercepted the Brazilian merchant ship Siqueira Campos near the Cape Verde archipelago. The submarine fired on it, and allowed it to proceed only after conducting an inspection. Since 1940, Brazilian ships had been seized on three occasions—Siqueira Campos, Buarque, and Itapé—by British authorities. These seizures were conducted under various pretexts, primarily related to the transportation of goods and/or passengers of German origin. On January 18, 1941, the British captured the French merchant ship Mendoza in the safety zone off the Brazilian coast. This event prompted the Brazilian government to issue a formal protest to the British government. France at the time, was under the Vichy regime).