Why was SALT II never ratified?

There were two Strategic Arms Limitation Treaties that were negotiated with the Soviet Union. The first treaty, called SALT I, was signed in Moscow in May 1972. The second treaty was negotiated and signed in Vienna in June 1979. However, the United States Senate never ratified the second treaty, known as SALT II.

The second treaty went to the U.S. Senate, but at President Carter’s request, the Senate never ratified it. The United States was upset with the Soviet Union’s invasion of Afghanistan in December 1979. When the Soviet Union refused to leave Afghanistan, one of our responses was not to ratify the treaty. Even though the U.S. Senate didn’t ratify the treaty, both countries agreed to follow the principles outlined in the treaty. The policy continued into the 1980s after President Carter left office and President Reagan took office.

Thus, the Soviet Union’s invasion of Afghanistan was the main reason why the United States Senate didn’t ratify the SALT II Treaty.