Michael Knights is the Jill and Jay Bernstein Fellow of The Washington Institute, specializing in the military and security affairs of Iraq, Iran, and the Persian Gulf states. He is a co-founder of the Militia Spotlight platform, which offers in-depth analysis of developments related to the Iranian-backed militias in Iraq and Syria.
Alex Almeida is the head security analyst at a leading risk advisory firm.
Losing Marib would discredit and debilitate the multilateral peace effort, so the United States should facilitate more energetic Saudi and Emirati support to the city’s defense.
Houthi forces are now as close as ten miles from the Yemeni city of Marib, which has been under rebel air and ground attack for the past fourteen months. If the city and its adjacent energy facilities fall, both Yemen’s fragile government and the U.S.-UN peace process will be in grave danger of disintegrating completely. This imminent risk necessitates robust steps to prevent a Houthi victory at Marib, which would essentially decide the war in their favor and reward their repeated breaches of UN de-escalation arrangements.
Why Marib Matters
At this stage of the war, Marib has attained tremendous symbolic and strategic value for several reasons:
Energy resources. The area is home to Yemen’s largest oil and natural gas fields, as well as its largest and most profitable bottling and distribution hub for cooking gas.
Alternative seat of government. The Houthis evicted President Abdu Rabu Mansour Hadi’s government from Sanaa when they seized the capital in 2015, and loyalist officials have only a tenuous presence in Yemen’s second-largest city, Aden. This makes Marib the largest Hadi-controlled city—and a strategically crucial one given its direct aviation and road links with Saudi Arabia, where the president currently resides. Marib also hosts three of the government’s regional military headquarters and the office of Defense Minister Mohammed Maqdashi, the senior ground forces commander.
Springboard for decisive offensives. Marib is situated at a key road junction connecting the southern governorates along the Gulf of Aden with Sanaa and Saudi Arabia. Seizing the city could allow the Houthis to mount rapid advances into oil-rich Shabwa governorate and toward the main Saudi border crossing.
Displaced persons. Around two million people currently reside in Marib, including well over a million internally displaced persons. If they begin to flee the city en masse, they would create a major refugee crisis in Saudi Arabia, Yemen’s eastern provinces, and Oman.
Trade hub. Marib has emerged from the war as a rare success story: a trade nexus that connects Houthi-held territories (and, by extension, the majority of Yemen’s population) with Saudi Arabia, Oman, and the Hadi-held provinces. If the war makes trading basic goods untenable in Marib, all Yemenis—including those in Houthi areas—will be nudged closer to famine.
Historical prestige. The city is home to the famous Marib Dam, which is referenced in the Quran and viewed by some as the wellspring of Arabia’s tribes.
The Battle for Marib
The Houthis nearly took the city in their 2015 offensive but were pushed back by Yemeni, Emirati, and Saudi forces over a period of two years. All of the buffer gained in that long counteroffensive has been lost since last year, however, enabled in part by two prior developments: the December 2018 Stockholm Agreement (a UN-brokered deal that ensured the Houthis could safely transfer commanders and forces from the Hodeida front to Marib) and the UAE’s withdrawal from most battlefields in 2019. Over the past fourteen months, the Houthis have advanced to within ten miles of northwest Marib. Battle sounds can be heard inside crowded neighborhoods, and rebel rocket strikes have escalated against the city itself.
The Houthi plan of attack has been simple and grindingly successful. It includes three elements:
Ground offensives. Every three months or so, the Houthis rebuild their attack force with child soldiers and other untrained conscripts. Overseen by a core of veterans and commanders, these conscripts are pushed forward in trucks and on foot in a pincer move against Marib: from the northwest along the Marib-Sanaa road and the open desert, and from the southwest to seize the key road link between Marib and Shabwa governorates. These offensives have been slowed to a crawl by stiffening defense around a cluster of hills west of the city. The forces responsible for this stand are a mix of tribal irregulars, militias affiliated with the Islamist-oriented Islah Party, and Islah-dominated brigades from the Yemen National Army. They are supported by well-placed Saudi airstrikes on Houthi concentrations attempting to hook north through the desert toward the vital Safer oil and gas facility. During heavy Houthi offensives, the Saudis have carried out as many as thirty such strikes daily, employing 1,000- and 2,000-pound bombs in open desert areas. Several hundred Houthi fighters have reportedly been killed in the past four weeks, the majority of them untrained child and adult conscripts.
Supporting bombardment of Marib. The Houthis have undertaken a number of accurate rocket and drone attacks within the city, beginning with a January 18, 2020, precision rocket strike that hit a mosque inside military headquarters during prayer time, killing scores of commanders and troops. Marib has been open to such strikes since the withdrawal of Emirati and Saudi missile defenses (the latter in 2019 to protect the kingdom), and Houthi drones constantly circle the city.
Strikes on Saudi airbases. By the end of 2019, Houthi strikes against the kingdom had decreased substantially as part of a UN-backed de-escalation effort. Yet they ramped back up in January 2020 with a series of rocket and drone attacks on Saudi airbases close to the border (23 in all, compared to 5-6 strikes per month in late 2019). Their apparent aim was to disrupt and distract Saudi air support to Marib, and this pattern persists today—Houthi advances are now timed to coincide with intensified rocket and drone attacks on Saudi Arabia’s main close air support base at Khamis Mushait and its drone and helicopter bases at Abha and Jizan. Rebels launched 29 such strikes this February and 27 in the first half of March, versus 5 in January before the latest offensive began.
Future U.S. Options
The U.S. government has rightfully condemned the Houthi push against Marib for threatening the peace process and accelerating the war. As mentioned previously, the city was made vulnerable when the Houthis were permitted to redeploy forces under the cover of UN-brokered de-escalation, and the Yemeni government has responded to the resultant emergency by reactivating other fronts in order to relieve pressure on Marib (e.g., the March 10 operation to lift the four-year siege of Taizz). The Marib offensive is also accelerating Houthi strikes into southwest Saudi Arabia, including against dual civilian/military airports. In return, the Saudis have been bombing Houthi missile and drone workshops inside so-called “de-escalation zones” in Sanaa and elsewhere. Meanwhile, the perceived fragility of the government’s position in Marib may encourage separatist maneuvering in the south and east, with potentially fatal consequences for peace diplomacy and Yemen’s territorial integrity.
This crisis was not precipitated by the Biden administration’s February 12 decision to delist the Houthi military wing as a designated terrorist organization—the Marib offensive started many months ago and made its biggest strides under the Trump administration. Yet the Houthis clearly disdain the new administration and feel they have nothing to lose by rejecting the peace plan suggested by U.S. special envoy Tim Lenderking, nor by doubling down on the Marib offensive and missile/drone strikes on Saudi Arabia. Washington and its partners need to change this impression—and soon, since the city could easily fall when the next Houthi offensive “pulse” occurs, probably within three months.
Rhetorical condemnation will not be enough to deter the Houthis; words must be paired with the tangible prospect of military defeat at Marib and cascading reversals on other fronts. Accordingly, the administration should use U.S. channels with the Southern Transitional Council (STC) to ensure that secessionists do not distract from Marib’s defense by making opportunistic moves elsewhere. Washington and its partners should also privately encourage Saudi Arabia and the UAE to quietly reinsert a handful of medium artillery units—namely, self-propelled 155-millimeter howitzers, surveillance drones, and short-range air defenses. Although neither country is keen to redeploy ground troops, shuffling such units between desert bases outside Marib could have a decisive effect on the battle. For its part, Washington should consider providing targeting intelligence against Houthi frontline commanders in situations where such strikes are deemed safe, putting the crosshairs on personnel that the Houthis cannot so easily replace.
Michael Knights is the Bernstein Fellow with The Washington Institute. Alex Almeida is the head security analyst at a leading risk advisory firm.