U.S and EU alliance
China and Russia
USA and the EU both have larger economies than China and Russia, the US military is large enough to solo Russia and China combined. And add the military of the EU on top of that, i'm pretty sure the US and EU would win. Though this war is very unlikely, especially considering how reliant we are on China for trade. Not to mention the other effects it would cause.
We have TEN TIMES the military spending or russia and china combined!
Even though China has about 1 Million more troops than us, with all the EU troops combined, we outnumber them!
This one would probably have a slight edge over the other. However last time China fought the US was in Korea so its really difficult to speculate what would happen.
I think the black bank would fund this side. He who has most funding wins..
Every time Russia gets involved in a war, someone's country collapses.