Estonia and other nations which make up NATO's Eastern Flank, along with the alliance as a whole, have a three-year window in which to avoid war with Russia, according to the head of Poland's National Security Bureau (BBN). Other expert estimates from European NATO member states put the time-frame at between five years and a decade.
You’re wrong about China, in my time in service we were always more wary of them than with Russia/NK.
China learned the lesson Russia failed to do, build an economy first and a military second. Sure they stole most of their R&D’d technology, but they have it, and they understand it well enough to keep up with our military technology. Unfortunately they also have the population and ability to mass produce that could keep a war machine turning for a long time even in a traditional engagement.
Are they as well trained? Probably not. They’re still a powerhouse of a country and our most significant threat.