The latest escalation threatens to drag Saudi Arabia and the Iran-backed Houthi militia back into a full-blown war. Strikes are a major escalation in conflict between important U.S. Key points and original sources are listed below.

• The latest escalation threatens to drag Saudi Arabia and the Iran-backed Houthi militia back into a full-blown war.S1

• Strikes are a major escalation in conflict between important U.S. ally and Iranian-backed rebels in YemenS2