Yemen: Recent Attacks Against U.S. Naval Vessels in the Red Sea


In recent weeks, the United States has been drawn deeper into the Yemen war, which has killed an estimated 10,000 people since it began in March 2015. In October 2016, military units allied with the Houthi movement and former Yemeni President Ali Abdullah Saleh (Houthi-Saleh forces) reportedly launched anti-ship missiles at U.S. Navy vessels on patrol off the coast of Yemen. While no U.S. warship was damaged, a similar attack earlier in October damaged a U.S. transport ship leased by the United Arab Emirates (UAE). The attacks against the U.S. ships marked the first time U.S. forces had come under direct fire in the near 20-month war.

The attacks may have been triggered by Saudi-led coalition airstrikes on October 8 that struck a funeral gathering of Houthi leaders in the capital Sana'a. Those strikes, which the coalition later described as having been mistakenly authorized, killed many civilians and prominent Houthi political and military leaders. Included among the casualties was the mayor of Sana'a, two Yemeni members of the U.N. cease-fire monitoring team, and several Houthi-Saleh high-ranking officers.

Such events in Yemen have elicited a multi-pronged Administration response. On the military front, the Administration responded to the attacks against U.S. naval vessels by firing cruise missiles against Houthi-Saleh radar installations. The Administration claims that those attacks were made in self-defense and has indicated that it does not want to deepen its direct involvement in the conflict. The October 8 Saudi airstrikes drew immediate condemnation and prompted the Administration to initiate an "immediate review" of U.S support for the Saudi-led coalition's military campaign. U.S. support had already been reduced in the preceding months amid concern that the coalition's repeated targeting of civilians was a violation of international law. From a diplomatic angle, the Obama Administration accelerated its efforts to broker a cease-fire in the hopes of deescalating the situation.

For Congress, recent developments in Yemen may be interpreted in a variety of ways. Some lawmakers may see the hand of Iran, a supporter of the Houthis, in supplying coastal defense missiles to Houthi-Saleh forces (or even Iranian proxies active in Houthi-Saleh controlled areas), and therefore reiterate the need to counter Iran's regional meddling. Others may be concerned that the Saudi-led coalition is too often targeting civilians using U.S.-origin military platforms and ordnance, raising questions about U.S. support for the coalition's military campaign. Some Members may stress broader concerns over the Houthi-Saleh forces' targeting of U.S. warships and other international vessels and potential implications of those attacks on maritime security and commercial traffic in the strategic Bab al Mandab strait, a global chokepoint for seaborne shipping that sits astride the coast of Yemen.

Table 1. Recent Events in Yemen



October 1, 2016

Image of HSV-2 Swift after it was attacked by Houthi-Saleh forces. (UAE Emirati media WAM)

Houthi-Saleh forces fire an anti-ship missile at the UAE vessel HSV-2 Swift, heavily damaging the transport ship which was transiting the Red Sea near the port of Mokha. Houthi-Saleh forces are believed to have used Chinese-built C-802s in the attack. The U.N. Security Council condemns the attack, saying that "Members take threats to shipping around Bab al-Mandab, a strategically important shipping passage, extremely seriously."

October 3, 2016

The Arleigh Burke class guided-missile destroyer USS Mason. (U.S. Navy Photo)

The U.S. Navy dispatches three ships, the USS Mason, the USS Nitze, and the USS Ponce to the southern coast of Yemen following the destruction of the UAE's HSV-2 Swift.

October 8, 2016

Destroyed great hall of ceremonies on al-Khamseen Street in Sana'a. (Associated Press)

Coalition air strikes hit a reception hall in Sana'a where prominent Houthi members had gathered to mourn the death of the father of a senior Houthi official. The death toll is estimated to have been 130 to 150, with hundreds more wounded. Many senior Houthi political and military figures are killed, as well as dozens of civilians.

October 8, 2016

In response to the strike, the Administration launches an "immediate review" of U.S. security cooperation with Saudi Arabia. According to a statement by National Security Council spokesperson Ned Price, "U.S. security cooperation with Saudi Arabia is not a blank check. Even as we assist Saudi Arabia regarding the defense of their territorial integrity, we have and will continue to express our serious concerns about the conflict in Yemen and how it has been waged."

October 9, 2016

The Chinese-manufactured C-802. Iran is a known operator of the C-802, having also supplied unknown quantities to Syria and Hezbollah. (Foundation for Defense of Democracies)

Houthi-Saleh forces fire two coastal defense cruise missiles at the USS Mason and the USS Ponce. The USS Mason employs counter-measures and the missiles fail to hit the ship.

October 12, 2016

Estimated range of C-802 missile in the Bab al Mandab Strait. (

Houthi-Saleh forces target the USS Mason. The ship responds with defensive fire and the attack is thwarted.

October 13, 2016

A Tomahawk Land Attack Missile Launched from USS Nitze against Houthi-Saleh radar. (U.S. Navy Image)

Claiming self-defense, the USS Nitze fires Tomahawk cruise missiles at three Houthi-Saleh-controlled radar installations, A Pentagon spokesperson says, "These limited self-defense strikes were conducted to protect our personnel, our ships and our freedom of navigation in this important maritime passageway," Other U.S. officials reiterate that U.S. actions do not indicate deeper U.S. support for the Saudi-led coalition or deeper military involvement in the conflict.

Iranian warships Alvand (right) and Bushehr (Radio Free Europe/Radio Liberty)

According to Iranian news, the Iranian navy dispatches two ships, the frigate Alvand and logistics ship Bushehr, to the Yemeni coast to "to protect the country's trade vessels against piracy." It is unclear whether Iran had already decided to deploy these vessels before the recent attacks against U.S. vessels.

October 15, 2016

In a deal brokered by Oman, Houthi militants release two unnamed U.S. citizens they had held captive in exchange for an emergency airlift of Yemenis wounded in the October 8 funeral attack.


The Saudi-led coalition's Joint Incidents Assessment Team (JIAT) issues a press statement concluding that the authorization of the October 8 airstrikes was mistaken.


The USS Mason may have come under attack for a third time, though this latest incident is under investigation by naval authorities. The Mason is not struck and no injuries were reported.

October 16, 2016

(Making a joint statement on Yemen, with left - right, U.S. Secretary of State John Kerry, British Foreign Secretary Boris Johnson and U.N. Special Envoy for Yemen Ismail Ould Cheikh Ahmed. VOA News)

Secretary of State John Kerry and UK Foreign Secretary Boris Johnson jointly call for all parties in Yemen to implement an immediate and unconditional ceasefire and move toward negotiations toward a final political settlement.

October 17, 2016

The United Nations announces that beginning on October 19, all sides have agreed to a 72-hour cease-fire that is subject to renewal. However, throughout the conflict, previous cease-fires have not lasted, and there are no indications that combatants are ready to negotiate a final political settlement.


The rapid progression of events in Yemen from early to mid-October has forced the Administration to deepen its involvement in the Yemen conflict by:

  • deploying more naval assets to the Bab al Mandab to protect international shipping;
  • deescalating tensions between combatants in order to restart negotiations; and
  • delaying further U.S. support to the Saudi-led coalition out of increased concern regarding civilian casualties from coalition airstrikes.

At the same time, the overall U.S. approach to the conflict remains the same: the Administration seeks to work multilaterally through the United Nations to pursue a cease-fire that ultimately jumpstarts negotiations toward a comprehensive political settlement to the conflict.

Policymakers and Members of Congress face the question of how the United States and others can maintain momentum to resolve the crisis. Lawmakers have already taken a vote on whether to disapprove an arms sale to Saudi Arabia, motivated, in part, by its conduct during the war.

Based on recent events, it would appear that the costs of the war in Yemen are spilling beyond its borders. Around 4% of global oil exports pass though the Bab al Mandab strait, the humanitarian situation in Yemen is dire and, if conflict in the Bab al Mandab were to continue, global shipping would have to be rerouted, thereby potentially driving up oil prices.

Figure 1. Escalation in the Red Sea

Source: American Enterprise Institute

However, the readiness of the combatants themselves for more than just a temporary cease-fire remains in doubt. The October 8 airstrikes may have hardened Houthi-Saleh forces and empowered the more radical elements of their alliance. Prior to the attacks, Houthi-Saleh forces demanded the resignation of Yemen's internationally-recognized president, Abdu Mansour al Hadi, and established an alternative ruling council. Hadi has moved the Central Bank of Yemen from Sana'a to Aden, and his Saudi-led coalition backers continue to insist that the Houthi-Saleh forces need to abide by United Nations Security Council Resolution 2216 and withdraw from territory they have captured, including the capital. It is unclear what leverage the United States or others in the international community have over the parties themselves to bridge these wide gaps.

Policymakers and Members of Congress may also assess the effect of the war in Yemen on tensions between the United States and Iran. Though there has been no firm evidence presented that Iran either directed or supplied the armaments used against the USS Mason and the UAE's HSV-2 Swift, Iran is a known supporter of the Houthis and the presence of Iranian warships in the Bab al Mandab/Gulf of Aden brings U.S. and Iranian forces into closer proximity. The Administration has sought to enlist Iranian cooperation in mitigating the effects of regional conflicts in the context of the multilateral nuclear deal, but open conflict with an Iran-supported group such as the Houthis threatens to heighten tensions.