Before the attack on Pearl Harbor, Americans were living life as usual. They were supplying other countries with no desire of war. They even passed a Lend Lease Act to make supplying other countries more business focused and neutral. Americans were at peace. President Franklin Roosevelt gave an addressed on October of 1940, “I have said this before, but I shall say it again and again and again; your boys are not going to be sent into any foreign wars.” Supplying other countries was business. That changed as Japan conquered northern French Indochina and expanded into China. The United States noticed this was going to be a big issue if Japan was not stopped. In 1940 they embargoed all scrap iron and oil to Japan which prolonged Japans expansion into China. This also led to Britain and the Netherlands cutting oil supply to Japan. This crippled Japans army effectively and became a big issue for Japan. This would force Japan to have to make quicker and better decisions with the limited amount of sources they had. Japan was riding on a huge momentum going into China, but the United States were starting to take that away from them little by little. The United States started looking more and more like an obstacle for Japan.
But those actions don’t count as participating or not participating in a war. The Lend Lease Act was made to look like supplying the Allies was just business. One can’t simply go to war with another country just because