The Soviet Union collapsed because their economy was crap and couldn't keep up with their military expenditures. The US, knowing this, won the Cold War by forcing the USSR to spend itself into oblivion as the Soviets tried to match the US tit for tat, in vain. This is common knowledge.
50 096 Subs? You *do* know the 096 would be an SSBN? It goes like this 091 SSN, 092 SSBN, 093 SSN, 094 SSBN, 095 SSN....096...wait for it...that's right! SSBN. But I'm sure that was just a typo on your part. A person that thinks a strong military and a strong economy are "mutually exclusive", to quote you, surely has a clear grasp of Chinese weapon platforms and how many of said platforms China would need to "level up" (or whatever video game analogy you're applying to a real life situation).
But come to think of it, Kim Jong Un also apparently believes that military expenditures and economic strength or mutually exclusive. And we all know how terrific North Korea is doing...