Most people only have a very vague idea how US national security and foreign policy decisions are made.
Most of the time, these decisions are made through the National Security Council (NSC) and its interagency process.
You might have heard of the NSC, which statutorily consists of the president; vice president; secretaries of state, defense, energy, and the treasury; and the national security advisor.
But the national security advisor also has a whole staff—usually people on rotation from places like the state department, pentagon, and intelligence community—that manages a vast interagency process.