\ What role did the United States play in creating and implementing alliances, both domestically and internationally?

Important role.

Explanation:

It should be understood that most countries of the world form alliances with the others for so many reasons. These include economy, technology, funding and so on.

And the U.S is not left out, so this alliance has given them a unique leverage in addressing various economic, diplomatic and geopolitical issues in those regions they have alliances with.

they thoght they were going to nuke each other