The US government has many military bases and troops stationed in other countries. It can project violence across the planet. Any entity with that power has strong ability to dictate what others do, and induce dependency.
https://globalaffairs.org/bluemarble/us-sending-more-troops-...
Safety of maritime shipping. The US Navy was created because ship captains kept getting ransomed by Moroccan pirates, since America gained independence their ships were no longer protected by the British Navy and became fair game.
I know it's a controversial doctrine, but power projection does have a hand in keeping the peace.