Iran Elevates Security Alert to Code 100 as Conflict Risks Escalate

Tehran announced on September 20 that it has placed its armed forces on the highest possible readiness status, known as “Code 100.” The alert, which covers the Islamic Revolutionary Guard Corps, the regular military and internal security units, was triggered by growing instability in the Middle East, especially after statements by IRGC lieutenant colonel Ibrahim Jolfagari on X.

Jolfagari warned that a U.S. strike on Yemen would imperil American personnel and could force the Bab al‑Mandeb Strait—a critical gateway between the Red Sea and the Gulf of Aden—to be closed to U.S. shipping. The passage handles a significant share of the world’s oil, gas and trade flows, and its closure would have severe repercussions for global markets.

Following Tehran’s move, U.S. embassies in Lebanon, Bahrain, Kuwait, Jordan, Qatar, Iraq, Israel, Oman, Saudi Arabia and Turkey issued advisory notices urging American citizens to stay vigilant, monitor travel plans, and expect possible disruptions to flights and airspace.

U.S. officials also pointed to Iran‑backed Houthi groups that have taken part in attacks against Saudi Arabia, including strikes on civilian airports, cautioning that the conflict could broaden quickly.

The heightened alerts signal that both Iranian and American authorities are preparing for rapid developments, and travelers are advised to keep a close watch on airline communications and embassy updates.