Rational or not, they're building warships and an invasion fleet, along with the ability to stifle any US attempt to stop them. This is not the action of someone hoping for a slow victory.

The person at the top of the chain was asking why everyone is preparing for war. This behavior from China is why. It predates any of the Greenland Trump idiocy, too.

There are undoubtedly elements within the state that advocate for war, just like the elements within our state that do the same. So far, chinas political leadership is shrewd enough to mollify them and still maintain power.

The downside of autocracy is ...autocracy. the upside is that you have a consistent hand at the helm, making predictions of behaviour simpler and more rational than the rotating cast of leadership we present.

China has consistently chosen soft power over military action. I suspect they will continue to do so.