In the desert Southwest, American soldiers rehearsed a kind of war that has not yet been fought but is increasingly imagined as inevitable — a high-technology confrontation with a peer adversary capable of matching, disrupting, or neutralizing the advantages the United States has long taken for granted. The exercise was less a display of strength than an honest reckoning with vulnerability, a deliberate search for the gaps that only pressure can reveal. Across simulated urban terrain, the military tested not just its weapons but its thinking, asking whether doctrine, logistics, and human judgm