Which action did the US not take to oppose aggressor Nations during and before entering in 1941?

Before entering World War II in 1941, the United States did not engage in direct military confrontation with aggressor nations such as Germany, Italy, or Japan. Instead, it focused on diplomatic efforts and economic measures, such as providing aid to Allies through the Lend-Lease Act and imposing trade embargoes, particularly on Japan. The U.S. also adopted a policy of isolationism, refraining from joining the conflict until the attack on Pearl Harbor in December 1941 prompted a direct military response.