In this case, their flooding problems are almost a godsend, otherwise they probably would have been looking to do some economic stimulation through some military actions.
You can upgrade schools, upgrade agricultural infrastructure, upgrade transport infrastructure, invest in space exploration, etc. Military is the worst possible method of economic stimulus.
They've been dumping money on infrastructure for decades now. Due to corruption, they could probably stand to go back and redo a lot of what was done previously, but with their luck, they'd tear down the stuff that was built properly and replace it with more of the bad stuff.
They're slowly working on space, but that's limited on the scope of economic engagement it provides. It also doesn't doesn't generate revenue, just costs(for now; although I'd
LOVE to see a space race 2.0 come kicking along at this stage).
Their transport infrastructure is a complicated matter, they have upgrades and expansions they could desperately use, but again, it can only be built so fast and requires specialized skills. (And leaves open the problem of what to do with those workers after the construction boom ends) Also, part of their belt-and-road initiative was an effort to outsource their engineers and contractors by getting other nations to buy into their debt-trap diplomacy approach to neo-colonialism where they get "loans" from China to pay for the work, where a loan default gives China a military or other strategic asset in exchange.
The list goes on and on. However, none of those activities does anything to address idle workers on the homefront due to factories being idled. The factories need to be getting used for something, and a military engaged in a war is really good at using things. If you can manage to win whatever war you engage in, you can even end up with even more things.
But you have to be able to win that war, and that means not attracting the attention of the world's currently reigning super-power.
