You're right that both China and Russia are threats, but not military threats in either case, but for different reasons. China doesn't threaten militarily and Russia's hands are tied by the M.A.D. threat, as are America'sOh, Russia is a bad actor for sure, how ever it's gdp is laughable. China is certainly the bigger threat. Keep sanctions on Russian economy will keep them in check. Better figure out what to about China.
The great danger that's to discuss is in the possibility that the Ukraine will attack and Russia will respond with massive force. And the possibility that Russia will suffer losses to US supplied weapons.
That's when proxy wars turn fatal for the powerful nuclear armed countries that participate.
Russia and China are already considering broadening the conflict to C.America and S.America.
Who knows what's going to happen in the future, but at least we have a few educated people contributing to the speculation on this topic.