Planning only/mostly for a limited conflict when both parties are well armed, large industrial powers is pretty short sighted (not to mention both nuclear powers).

Conflicts escalate in unpredictable ways across history because once you start it's really hard to stop sometimes.

The US has grown used to been able to enter a war on its terms and exit on its terms and against the people they've been fighting since Korea that's been entirely possible because they can just leave and the combatants on the other side couldn't really do a lot to the US once they'd gone.

China isn't that.