The U.S. has halted its bombing campaign against Iran after 13 nights, not by choice but because it is running out of missile interceptors — bad news for American troops still in range.

• The Pentagon has burned through its Patriot interceptors and other air defenses, forcing a pause in strikes.
• Top military leadership privately told Trump that restarting major operations would leave Central Command dangerously short of interceptors.
• The administration claims about a thousand interceptors remain; former intelligence analysts put the real number closer to 400.
• U.S. casualties are climbing — 18 troops dead and more than 600 wounded since the war began in late February, including three killed in Jordan when a ballistic missile got past American defenses.
• The bombing appears to be backfiring, rallying Iranians around their leaders rather than pushing them to negotiate, and Iran still holds most of its ballistic missiles.

Outlook: The pause is likely to hold as long as supplies stay thin, but nothing suggests Iran is moving toward talks.