Potential MILITARY pool a lot larger than the TOTAL U.S. population...
Which means in a war with U.S. forces on the mainland they could absorb a LOT of damage and KEEP ON FIGHTING probably indefinitely.
But then no one envisions the U.S. invading China to fight a land war...nor Chinese armadas invading California...
DEFENDING against the minority of PRC forces that could invade Taiwan is a lot more thinkable...hence the multi carrier battlegroup exercise 'show of force' last summer...but it would be FAR from quick or easy or painless...and the risk of escalation to nuclear confrontation by miscalculation would be worrisome...:-(
Well then I say risk it. We risked nuclear war to protect the ungreatful western europeans.