Both the United States and Canada are , but with different methods of government. The US is a <em>republic</em>, with a<em> congress and a president</em>, who is, at the same time, the head of state and the head of government. Also, there is separation of powers. Canada has a prime minister, who is a member of the <em>parliament.</em> There are two official languages in Canada.
The policy was called M.A.D or mutually assured destruction. It meant that if a nuclear war started both countries would be destroyed and there would be no winner.