If the U.S. is no longer Leader of the Free World, then what is left is a multipolar world, the main poles being the U.S., Russia, China, India, and the European Union -- not including the UK, which is no longer one of the main poles, sorry, old chaps, hard cheese!
Which means a complex and shifting web of alliances and hostilities among those poles will develop. It will be much like Europe in the runup to WWI. Knock wood and spit.
Which means a complex and shifting web of alliances and hostilities among those poles will develop. It will be much like Europe in the runup to WWI. Knock wood and spit.