U. s. foreign policy decisions are most affected by the federal government’s responsibility for — 1health care 2national security 3treaty negotiations 4commerce regulations

2. national security 

U.S. foreign policy decisions are most affected by the federal government’s responsibility for national security. This is always the top priority in the foreign policy, as it is essential for the federal government to be able to protect the United States from any form of attack both inside the federal territories and outside. 

Because he proposed that all the treaties should be made through the league of nations.