This writing explains the factors driving the United States' support for the new military law in Japan. as Japan had known after World War II was under the United States in terms of security and influenced constitutional changes in Japan known as Article 9 of the Japanese Constitution. this made Japan implement a passive military system. Japan is not allowed to use weapons and the military in resolving international issues. In 2015, Japan revised article 9 of the Japanese constitution. which means that the role of the Japanese military, called the SDF, is becoming more proactive and Japan can send peacekeeping forces abroad. this is supported by the United States which has been the umbrella of Japanese security since the end of World War II. This study aims to identify the reasons for the United States in supporting changes in new military policies in Japan. in changing policies that have persisted for years and become a new Japanese state.