Concern about the status of U.S. munitions inventories has intensified as reports emerge about high expenditures of Tomahawks, Patriots, and other missiles in the Iran war. As Operation Epic Fury remains paused in a shaky ceasefire, there is an opportunity to assess whether the U.S. military nears the point of going “Winchester”—or running out of ammunition. Analysis of seven key munitions shows that the United States has enough missiles to continue fighting this war under any plausible scenario. The risk—which will persist for many years—lies in future wars. In the 39 days of the air and missile campaign before the...