Who is skilled and understands weapons technology.
From USA to Russia to China.
Detailed analysis should be given.
China clearly much manpower, USA has discipline and nukes (B61-12 'Gravity' Bomb), advanced laser weapons (LaWS) and many efficient biological projects (like DARPA etc) "soldier enhancement" programs.
Russia clearly having (currently) the strongest submarine mounted nuke (Knyaz Vladimir?) and having very much land opportunity and mental discipline, plus also an accelerated biological program for troops.
This can be an interesting (hypothetical) but absolutely PEACEFUL discussion, here, at Area-1255.