The USS Mason, an Arleigh-Burke class destroyer, fired three missiles in self-defense against Iranian-backed Houthi rebels who launched cruise missiles at it and other US navy warships.  The Arleigh-Burke destroyers are built around the Aegis ballistic missile defense system, and are also equipped with weapons and countermeasures designed to handle cruise missiles.  The attack represents the first time these systems have actually been used in combat to protect a Navy ship.

The attack on the Mason comes after the outright destruction of a UAE warship by a similar missile attack carried out by the Houthi rebels.  The HSV-2 Swift, designed by the US Navy but in use by the UAE’s government, was destroyed by an explosively-formed penetrator (EFP) warhead.  This warhead follows the same form as the infamous roadside bomb that was characteristically used by Iranian proxy forces in the murder of US troops in Iraq and Afghanistan.  The EFP involves a copper plate that is worked in such a way as to collapse into a slug when fired from a tube by a high explosive.  That slug can then punch through the strongest armor.  In the roadside bomb, it would be used to attack American armored troop transports in order to kill the soldiers inside.  The cruise missile warhead is designed to go off once the outer part of the warship penetrates ship armor, sending EFPs in multiple directions to punch holes through the hull in many places.

The Swift was engaged in transporting medical aid at the time it was destroyed by Iranian proxy forces.  The deployment of the Mason and its fellow ships was in response to the destruction of the Swift.  In addition to another destroyer, the afloat forward staging base USS Ponce has been sent to assist the coalition operating against the Houthi in Yemen.  They are part of the USS Dwight D. Eisenhower carrier strike group.

The attack is part of a game of increasing attacks on American forces intended to drive them out of the region.  Iran has led the effort here, both through its actual warships and through proxy units like the Houthi, its Iraq-based Shia militias, and the Syrian air force.  In addition to Iran and its proxies, the Russians have been aggressively seeking to drive American warships from contested waters.  Last year Iran went so far as to intercept and kidnap American sailors operating in US Navy boats near Iran.

The conflict in Yemen is explosive because it pits Sunnis against Shias, on the border with Saudi Arabia, in a way that would allow Iranian influence to flank the Saudis.  A coalition of Sunni powers is fighting against the tribal Houthi, who participate in a form of Shia Islam that is rather milder and less apocalyptic than Iran’s own.  The civil war in Yemen has drug on for years, and shows no sign of being resolved.  The increasingly aggressive tactics, now targeting even US ships, may be intended to derail support for the Sunni coalition in a way that would allow for a Houthi victory.