Huge risks in shunting surplus energy into the forces. 20% youth unemployment drives hard but once bullets start flying at the Taiwan straights or the spratleys you have to distinguish between the Potemkin village solders and the ones who actually can do the job. Most of the risk is seaborne, and the navy can't handle that many more recruits, so you have army boys and girls and nothing to do with them: Vietnam is not a good idea, it's a corgi with sharp teeth. Dont pet the dog if you want to keep all your fingers. India well sure you CAN stop fighting with rakes and shovels but it's a long way west and for what? To sell internet to Bhutan?

And, bodybags are a bad look for the government. Serious numbers of Chinese now have family permanently overseas in Australia, New Zealand, the US and Canada and they don't only read qq.com and taobao and wechat. So, the whole "we own the story" dynamic here is weak too: people may not talk about tienanmen but they are talking about how Xi is missing his half of the social contract.

He governs at the will of the people. If cheap housing, jobs, food and android phones dry up, the will of the people dries up too. There are plenty of populists a few decades younger than Xi who can rally popular support and people discount how strong the provinces are: if they block the roads and food trucks into Beijing stop coming, the PLA has to fight its own grandma and cousins. Nobody likes this. Driving tanks over anonymous students in the square is one thing, but provincial troops beating up aunty and uncle another. Central government usually caves in to provincial backlash.

In any case it only buys you so much time: the people come out of their time in the PLA and then what?

Repurposing the forces for domestic construction projects might pay off, mass rural electrification, conversion out from coal, better roads and more rail. So WPA but on steroids.

Building out airstrips along the nine dash line won't soak up enough labour.