In Brazil, the Brazilian Armed Forces (BAF) are the second largest military in the Western Hemisphere behind the US; they are responsible for external security and protecting the country's sovereignty but also have a considerable internal security role; the BAF’s missions include patrolling and protecting the country’s long borders and coastline and extensive territorial waters and river network, assisting with internal security, providing domestic disaster response and humanitarian assistance, and participating in multinational peacekeeping missions

in the past decade, the BAF has mobilized thousands of troops to conduct counternarcotics operations, support the police in combating crime, assist with disease outbreaks and humanitarian missions, and provide security for major events such as the 2014 World Cup and the 2016 Summer Olympics; it has also cooperated regularly with neighboring countries such as Argentina and Paraguay on border security to combat smuggling and trafficking 

Brazil has Major Non-NATO Ally (MNNA) status with the US, a designation under US law that provides foreign partners with certain benefits in the areas of defense trade and security cooperation

the origins of Brazil's military stretch back to the 1640s; Brazil provided a 25,000-man expeditionary force with air and ground units to fight with the Allies in the Mediterranean Theater during World War II; the Navy participated in the Battle of the Atlantic (2024)