Of course, America's abdication means that China will rule the roost from now on.
The Trump-branded US looks like it is determined to become irrelevant on the global stage, except as a military force. So its influence will be imperial where it is relevant. And that is a more expensive route than persuasion and peaceful trade. Where its force is absent, it will simply be disregarded.
The US is in the process of ditching its allies, as we can see all over the place. And of course, without allies, it is going to be harder for the US to project its power.
Prediction.
The old English imperial alliances look likely to reemerge, but with Indian leadership far more prominent. Canada, UK, Australia, NZ, India and others is a very large landmass, population, financial, common law and economic area. This will replace the US in terms of diplomatic influence on the global stage. The EU will turn towards Russia more, as the US is hostile. It will also create its own armies as NATO dissolves. Mexico will look southwards and the Latin nations will seek to synchronise themselves. Russia will recover its influence over former Soviet territories.