Did the US have significant interests in Korea? Vietnam? Lebanon? Somalia? Bosnia? Rwanda? Syria? Libya?I dont see the US as ever having fulfilled that role. They simply furthered their goals by any means necessary and sometimes it ended up working to this effect.
Even if the US decided tomorrow to close all its overseas bases and cancel all its alliances the world wouldnt erupt into chaos.
China will take over taiwan and russia might finish taking ukraine but wars are a thing that even with the US influence still happens and in recent times often even started by the US so no significant change there.
People often forget how nasty the Communists were. South Korea is much better off than North Korea, for example. Would Europe have fallen to the Soviets without an American counterweight?
How did the US benefit from Somalia? Did we steal oil from Iraq? The Europeans definately took raw materials from nations that they "helped."
Are you sure that the Russians would stop with the UKR? Would China stop with Taiwan? What would Iran do to Iraq and/or the Gulf states? Pakistan and India? What would happen in the Arab-Israel saga?