He told the New York Times that he thinks the U.S. will “very likely” find itself in a three-front war with China, Russia, and Iran. As a result, he said, the Pentagon should continue developing autonomous weapons at full speed, pointing to big mismatches in how far the U.S. would be willing to go while fighting a war compared with other countries.
True but China really doesn't need to strike the heartland. All of their war goals and strategic interests are south east Asia. The only reason they might want to conduct strikes on the US would be preemptive attacks to disable ICBMs and long range bombers.
If China/US war broke out tomorrow their primary targets would be Taiwan, Japan and Korea. UD calculus would be to either come get involved and counter those pushes, or abandon their longtime allies in the region, which would send a dangerous signal to other US allies and partners abroad. Even if Trump wanted to avoid a war with China, US Navy has too many assets tied up in SEA to just turn away.