In foreign policy, Reagan ended detente (the policy of being friendly to the Soviet Union) by ordering the largest peacetime military buildup in American history. The U.S. government had to borrow a lot of money to pay for it. He had many new weapons built. Soon, the U.S. began to research on a missile defense system which would destroy missiles. It was to prevent a nuclear war from happening. The program was called Strategic Defense Initiative. It was nicked named "Star Wars".