Former President Donald Trump has proposed utilizing crime-ridden U.S. cities as military training grounds, arguing that urban crime represents a modern battleground requiring unconventional military responses. He suggested deploying military units, beyond the National Guard, in cities like Chicago, San Francisco, New York, and Los Angeles, framing the domestic crime issue as a “war from within.” This initiative, which seeks to address escalating violence through federal intervention, may alter traditional perceptions of national defense and provoke concerns over military overreach in domestic law enforcement. While likely appealing to advocates of law-and-order policies, critics may view this approach as a potential infringement on civil liberties and local governance, raising significant questions about the balance of power in U.S. civil-military relations.