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Policy Analysis

PolicyWatch 3037

U.S.-Saudi Security Cooperation (Part 2): Restricting Operational Support in Yemen

Michael Knights and Lt. Col. August Pfluger, USAF

Also available in العربية

November 6, 2018

The United States should keep training and advising Saudi forces if they meet certain conditions, but it should end refueling support to Saudi aircraft operating near Yemen.

This PolicyWatch is the second in a two-part series on potential adjustments to the bilateral security relationship. Part 1 offered recommendations on delaying and conditioning arms sales to Saudi Arabia.

Last week, Secretary of State Mike Pompeo and Defense Secretary Jim Mattis laid out a sequence for ending hostilities in Yemen: the Houthi rebels are expected to cease border and missile attacks, after which the Saudi-led coalition is to halt high-risk airstrikes in populated areas, thus laying the ground for peace talks. Yet if the hoped-for talks wind up failing (as the previous round did earlier this year in Geneva when the Houthis refused to attend), Washington will likely intensify its scrutiny of U.S. operational support to the Saudi war effort. Since the conflict began in 2015, Congress has debated whether to end support activities such as refueling coalition aircraft and providing advise/assist functions in Saudi Arabia. Yet discussion of these missions often loses sight of their limited scale and, in the case of advisory support, their crucial defensive and diplomatic value.


Saudi operations in Yemen are evolving. The air war is slowing down and becoming more selective, with air-dropped weapon releases declining from nearly 200 per day in the early weeks of the war to less than 10 per day in 2018. On the ground, however, the Saudi military presence inside Yemen has expanded from well under 1,000 troops at the beginning of this year to around 3,000 today, comprising elements of six brigades from the Saudi Arabian National Guard (SANG) and Royal Saudi Land Forces.

Although the U.S. military plays a very minor role in directly supporting operations in Yemen, the Saudi war effort draws indirectly on the large U.S. training missions and contractor support services that keep the kingdom’s armed forces operating. These programs, which are fully funded by the Saudi government, include:

  • The U.S. Military Training Mission. Operating continuously since the 1950s, the 200-strong USMTM is based in Riyadh and works directly with each branch of the Defense Ministry, fulfilling the crucial role of processing U.S. Foreign Military Sales from concept through delivery. This mission has never been withdrawn from the country during any crisis, even when the United States removed its air operations headquarters from Prince Sultan Air Base in 2002.
  • OPM-SANG. Another few hundred U.S. military personnel and contractors oversee the U.S. Army’s Office of the Program Manager-Saudi Arabian National Guard (OPM-SANG). This mission has operated continuously since 1973 to organize, equip, and train SANG, a multi-brigade collection of armored infantry, helicopters, and artillery that has become the kingdom’s second-largest land force.
  • MoI-MAG. In 2008, the U.S. Army set up a smaller Ministry of Interior-Military Assistance Group to help the Saudis develop critical infrastructure security capabilities and build out their Facilities Security Forces, Special Security Forces, Border Guards, and General Security Aviation Command. This training mission contributes to protecting the world’s largest energy installations, fighting terrorism, and developing the Border Guards, the force that has suffered the highest casualties in the Yemen war due to Houthi raids into Saudi Arabia.


On June 8, the Trump administration acknowledged that U.S. forces “have continued to provide military advice and limited information, logistics, and other support to regional forces combating the Houthi insurgency in Yemen,” though he made clear that this was “a non-combat role.” This support includes:

  • Advice on lawful targeting. On February 27, the Pentagon informed Congress that a small number of U.S. personnel were providing “advice regarding compliance with the law of armed conflict and best practices for reducing the risk of civilian casualties.” Secretary Mattis confirmed this point on October 30, describing how legal and weapons advisors are working to improve the capabilities of Gulf coalition forces so that “they are not killing innocent people.”
  • Border and missile defense assistance. On April 17, Assistant Defense Secretary for International Security Affairs Robert Karem told Congress that “roughly 50” U.S. personnel had been deployed to Saudi Arabia to advise “on Houthi ballistic missile threats to the kingdom.” Media outlets have reported that U.S. personnel are also helping Saudi border forces reduce their casualties from Houthi roadside bombs.


The latest statistics from U.S. Central Command suggest that American forces are supporting the Saudi air campaign in Yemen with an average of 101 refueling sorties per month, or around 3 per day. In military terminology, this means that approximately 400,000 pounds of daily “offload” is available to Saudi aircraft involved in fighter missions, command and control, intelligence, and reconnaissance. The kingdom pays for the fuel and can call for deliveries as part of the bilateral Acquisition and Cross-Servicing Agreement, which gives the United States various logistical and access rights as well.

In total, fuel deliveries to Saudi aircraft amount to less than 5 percent of the U.S. Air Force’s daily deliveries in Iraq, Syria, and Afghanistan. Moreover, Secretary Mattis recently noted that the USAF provides less than 20 percent of the fuel consumed in daily Saudi air operations over Yemen—more than 80 percent is provided by the Royal Saudi Air Force’s thirteen large air refueling platforms.

In other words, if Washington reduces or cancels this refueling support, it would have minimal effect on Saudi operations inside Yemen—with one important exception. In general, the kingdom’s air force operates relatively close to Saudi airfields, thereby reducing the overall offload requirement for air-to-air refueling. Defensive operations on the border would not be affected because they are undertaken at a range of 150 nautical miles from the main airbase at Khamis Mushait. Yet a refueling cutoff could complicate Saudi operations deeper inside Yemen, such as opportunistic airstrikes in Sana, Saada, and other urban locales that present a high risk of civilian casualties. On October 30, Secretary Pompeo stated that coalition airstrikes “must cease in all populated areas in Yemen,” suggesting that a cutoff might be a useful way of signaling Riyadh and shaping Saudi operations.


If the latest push for peace talks falls apart, U.S. officials may seek to distance America even further from the Yemen war via punitive measures against Riyadh. Yet while some of these potential measures are reversible options that offer a good means of signaling displeasure, others would damage Saudi Arabia’s legitimate defensive efforts and may prove difficult to reverse. Policymakers should be realistic about the minimal role that U.S. forces actually play in directly supporting the war. Going forward, Washington should limit itself to the following steps:

  • Continue military training missions. USMTM, OPM-SANG, and MoI-MAG are vital sources of U.S. influence and access in Saudi Arabia and are highly valued by both governments. Although this makes them very powerful cards to play, it also underlines how going too far could undo half a century’s worth of defense diplomacy. These missions will never be a foolproof way of preventing Riyadh from acting on its own perceived interests, but they have served as a vital channel of high-level dialogue through dozens of revolutions, wars, and energy crises.
  • Continue advise-and-assist support to defensive missions. According to Washington Institute data obtained from research along the Saudi-Yemeni frontier, the kingdom has suffered hundreds of fatalities each year from attacks on its Border Guards and missile strikes on southern Saudi towns. The United States should continue helping the Saudis defend their territory, including through increased defensive aid to hard-hit border units.
  • Keep advising Saudi forces on lawful targeting. Critics correctly argue that Saudi Arabia is not amending its targeting policies fast enough despite U.S. advice, but that does not mean giving up is the correct solution. Preventing additional civilian casualties is the most important contribution Washington can make, and this effort should not be politicized. To put more pressure on Riyadh without rescinding advisory support on targeting policy, the United States should condition future training and advise/assist efforts on Saudi forces halting their airstrikes against Houthi leadership targets and high-risk populated areas.
  • Stop refueling aircraft near Yemen. Although U.S. refueling support is not critical to the overall Saudi air campaign, withholding it from aircraft operating near the border might force Riyadh to reduce the number of emerging targets it attacks in Sana and Saada, where airstrikes have caused the worst civilian death tolls.

Michael Knights, a senior fellow with The Washington Institute, visited Yemen and the Gulf coalition states four times this year to observe military operations on multiple fronts. Lt. Col. August Pfluger, USAF, is a military fellow at the Institute.