Could US subterranean warfare be a future threat to China’s military defences?

Chinese think tanks have warned that the United States may be developing underground warfare capabilities, posing a potential threat to China's national security. Military theorists are exploring the strategic potential of subterranean space as a future dimension of warfare, particularly as drones and precision-guided weapons become more prevalent in ground combat. Palmer Luckey, founder of Anduril, has promoted the concept of a "subterrene," a vehicle designed to move through the Earth's crust similarly to how submarines operate underwater. This development suggests a potential shift in military strategy towards exploiting underground environments.