What foreign policy goal does the united states advance by participating in the north atlantic treaty

NATO has two main benefits for the United States and other nations involved:

The first is from a political standpoint. All members of NATO share democratic values, and they are all encouraged to prevent conflict and cooperate with one another on security and defense problems.

The second is from a military standpoint. NATO works towards maintaining peaceful relationships with outside nations. However, if a conflict arises, NATO has an agreement called "crisis-management." This means that the members of the North Atlantic Treaty Agreement work together to provide whatever military and security measures are needed to protect the NATO territory.

This is beneficial to the United States because being a member of NATO guarantees some political and military assistance if conflict ever comes to American ground.