All of the rest of the world, including Europe and China, will go down too. There's an old saying: "When Wall Street sneezes, the rest of the world develops pneumonia".

China can only maintain the (limited) standard of living that their people enjoy right now because the US and Europe buy their stuff. They may be planning on hundreds of power plants, but the key components of those plants come from the western world. China is just barely getting to the point that the US and England were in in 1950, being able to build jet engines that last more than 100 hours: That technology has application to power plants as well.

Europe (especially western Europe) is barely hanging on now. Generations of welfare entitlements and nearly unrestricted immigration from the arab world have created a situation where there are not enough jobs for everyone, but everyone gets welfare - either direct welfare, or 'students' who are paid to attend university for a decade or more without getting a degree or joining the work force. Combine that with a less than replacement birth rate and very generous retirement programs and you have a situation where people demand that the 'government' take care of them and the 'government' doesn't have the ability to. While the European heritage Frenchmen and Belgians, etc may not riot when their checks stop, you can be sure that the 'youths' will start with car-b-ques and move up from there. As it is they burn cars just about every night in Paris and the police refuse to even attempt to stop them - they'd be lynched. They just stay the hell out of those neighborhoods.

And while the EU may have a GDP of about the same per capita as the US, the standard of living there especially in the big cities, is far lower than in the US, mainly due to taxes. Gasoline, for example is about $10 per gallon in England - a country that has substantial north sea oil production. That extra money goes to taxes to support the welfare system.