Brazil nuclear

The Brazilian nuclear weapons program started in the 1960s, when Brazil was the South American leader in nuclear technology research and development, competing only with Argentina in a proxy-Cold War in order to receive software and equipment from Europe and the United States. However, in 1980, Brazil signed the Agreement on the Peaceful Use of Nuclear Energy with Argentina.

Thereafter, the two countries abandoned their nuclear weapons' ambitions and became peaceful nuclear powers. Brazil also became a signatory of the 1967 Treaty of Tlatelolco (officially called the Treaty for the Prohibition of Nuclear Weapons in Latin America and the Caribbean) as well as the Nuclear Non-Proliferation Treaty (NPT).

The Brazilian Constitution mandates peaceful usage of nuclear power - for energy and for medical research. Brazil currently operates two nuclear plants (Angra I and Angra II) and is building a third (Angra III). It hopes to build five more such units in the next ten years.

Although there continues to be some speculation as to Brazil's nuclear program and its potential for weapons manufacturing, the country has continued to pledge to enrich its uranium (U-235) to only 3.5%, which is drastically below the level required to fuel an A bomb (a minimum of 90%).

However, Brazil does posses a "breakout capability" - the ability to manufacture nuclear weapons before the world can react - due to its stockpile of uranium that has already been enriched to 3.5%-5%. The United States worries that Brazil, like Iran, may be able to execute a fait accompli.

Brazil's 2009 nuclear submarine project caused some tension between Washington and Brasília because the program was considered a per se violation of the Treaty of Tlatelolco and ultimately threatened U.S. hegemony in the Americas.