Guidelines for the Brazilian nuclear policy in Costa e Silva’s government (1967-1969) and defines the diplomatic attitude of Brazil regarding the negotiations of the Non-Proliferation Treaty (NPT). During the meeting of the National Security Council, participants agreed on the need to cooperate with another country to start a national nuclear program. On the NPT negotiations, the members of the National Security Council agreed to establish a condition to adhere to the Treaty: the defense of the right to develop peaceful nuclear explosions. Several ministers defended the possibility of using nuclear energy in the future for international security reasons.