How is the PLA constrained? It's building up its military strength at a rapid pace and without any limit; you spend enough time on this forum to know that. China is even openly expanding its nuclear deterrent and the only response the US could come up with was putting some (wrong) Chinese flags on an empty table. How laughable.
Quite frankly, the only reason there's peace is because peace suits China's interest. It can build up its military unimpeded, so why start a risky war today when your enemy's going to be a pushover tomorrow.
Yeah, until that day. I don't know what you do for a living, but one field I don't think you're suited for (no offense) is marketing bulletproof vests. I imagine your sales pitch to potential customers would be, "This vest is great! It works every day until the day you get shot."
Strategic patience is all China needs because it's the winning move.