Why did you sign the US-Japan security treaty?

Security Treaty between the United States of America and Japan

It was signed by the United States and Japan in Washington on June +0960, 5438 and June+10/9, 5438. This treaty declares that the two countries will jointly maintain and develop their armed forces to resist armed attacks, and at the same time acknowledges that Japan's attack on one country is harmful to another country, including the provisions of the US military stationed in Japan. The treaty strengthened the relationship between the United States and Japan during the Cold War, and also included provisions for further international and economic cooperation.