While China has some economic influence outside of Asia, it is fairly minuscule when you compare it with the kind of diplomatic (and military) pressure that the US (and the USSR) could bring to bear in those regions. Economic influence is quite limited in power once the stakes are raised (it certainly isn't working in Europe, Australia, Japan, or India), and certainly isn't going to buy more than verbal support from countries in Africa or Latin America.

I don't consider Germany a great power - any influence they have is economic only, and greatly diluted through the EU (as the EU was designed to do). Russia is a Great Power in its near abroad (Eastern Europe, Central Asia, Balkans, Middle East), you can consider the EU as a whole a great power if they can actually ever coordinate on anything, and of course China is a Great Power in Asia. Japan hasn't yet embraced the military, economic, and diplomatic resources and strategy required to currently be a rival Great Power to China in Asia, but it has the capability to do so, and is slowly working its way towards doing so.

The US is still the only global SuperPower, able to bring overwhelming influence into all parts of the globe, whether it is diplomatic, economic, or even military. It's part of the reason the US has 11 aircraft carriers, 800 ? overseas bases, and running trillion dollar deficits with the largest economy in the world.