The civil war in Yemen that erupted in 2014 rapidly became a proxy fight, with the Saudi-led military coalition squaring off against the Iranian-backed Houthi rebels, who have seized control of much of the western part of the country, including many of the major population centers. As a result, Yemen’s civil war has generated long-term geopolitical turmoil that extends well beyond the Gulf, drawing regional and global powers into the conflict. Russia in particular is playing a growing role of late, and as the war drags on with no end in sight, it continues to expand its footprint in the country. As it has in Syria, Russia seems to be outmaneuvering the West in Yemen.

Moscow maintains close contact with all sides of the conflict and has offered its assistance in working toward a resolution, even as it pursues its own military, commercial, and maritime interests. Russia’s growing involvement in Yemen was partially prompted by the failure of the U.S, France, the U.K, and the Saudi-led coalition to resolve the conflict, and Moscow has assumed a greater role as a mediator between the Houthi separatists and the internationally recognized Hadi government. In January 2018, Abdulmalik al-Mekhlafi, Yemen’s foreign minister, went to Moscow to meet with Sergey Lavrov, his Russian counterpart. The Russian government has also previously hosted informal discussions with Yemeni political factions backed by both Saudi Arabia and Iran, including a Houthi delegation to Moscow in February 2015.

While Russia had initially supported the Houthis in the conflict, it shifted its stance following their assassination of former Yemeni President Ali Abdullah Saleh in Sana’a in December 2017. Saleh, a secular strongman, had openly expressed support for greater Russian involvement in the crisis in 2016, and in the wake of his death, Moscow accused the Houthis of being a destabilizing force in Yemen and called fora political solution to end the crisis. For the most part, though, Moscow has refrained from being overly critical of the Houthis, at least publicly, with an eye to encouraging them to accept Russia’s offer to mediate. Russia’s interests and involvement in Yemen are not limited to diplomatic talks and informal mediation, however. Yemen’s seaports are strategically important in the Gulf region, and Moscow has sought to secure access for its naval fleet, most notably to the port at Aden.

Access to Aden, which the Soviet fleet had during the Cold War, would expand the reach of the Russian navy in the Middle East, adding a fourth maintenance and repair facility in the corridor running from the Suez Canal through the Arabian Sea to its existing depots in Alexandria, Aqaba, and Fujairah. Russia also has its eyes on the island of Socotra. Establishing a foothold there would be beneficial as Russia looks to expand its military and commercial maritime interests in the Red Sea and the Gulf of Aden. As Russia works to expand its influence and role in Yemen, the use of private military companies (PMCs) has been central to its efforts. The Russian PMC phenomenon began in 2014 with the emergence of various private paramilitary groups in eastern Ukraine and Syria. Since then, the Russian state has perfected a system whereby retired servicemen are recruited and sent to conflict zones as contractors under the banner of PMCs. In recent years the use of PMCs in different conflict zones has expanded significantly.

Many of their actions remain secret, and some suggest that Russia employs them in such situations to avoid having to report deaths, which would be required with regular Russian forces. Russian PMCsare primarily staffed by veterans and former officers of the military intelligence agency (GRU) and the Federal Security Service (FSB). The first report that Russian PMCs were operating in Yemen came on Sept. 6, 2018, when Russian military correspondent Semen Pegov posted that “members of one Russian Private Military Company [are] being currently deployed in Yemen.”He attributed the information to “three anonymous sources in the siloviki security services personnel] circles.” Russian officials reportedly authorized PMC operations in Yemen after Houthi leader Mahdi al-Mashat requested that Russian president Vladimir Putin “help end the civil war.”

Although the official response from the Russian government did not refer to PMCs, it is likely, given what happened in Syria, that they have played a significant part in Russia’s involvement. Much about the role of Russian PMCs in Yemen remains murky, however. To begin with, it is unclear which PMCs specifically have been deployed. Wagner Group is perhaps the best-well-known Russian PMC, but it is unlikely to be active in Yemen given its bad reputation and actions in Eastern Ukraine. It is more likely that PatriotGroup, a better manned and equipped PMC, has been deployed, given that Russia seems eager to maintain a positive image as a peacemaker in Yemen. Another question that needs to be answered is how Russian contractors managed to enter Yemen in the first place, given that the country’s main borders (land, sea, and air) have all been sealed by the Saudi-led coalition.

The most likely explanation is that Russian fighters were allowed to enter Yemen via Saudi Arabia, given the current strong relationship between Riyadh and Moscow. The Russian-Saudi thaw began in 2015, as a result of geopolitical factors like the Iran nuclear deal, Western sanctions on Russia, the war in Yemen, and Moscow’s military deployment in Syria. Both states acknowledged each other’s importance in the region and decided to focus on areas where they could find common ground, culminating in KingSalman’s official visit to Russia in October 2017. It is also unclear what exactly the Russian PMCs’ mission is in Yemen. In line with Russia’s stance on the conflict following the assassination of former president Saleh, the PMCs are unlikely to be involved in direct fighting, instead of focusing on providing battlefield assistance for the Saudi-led coalition and supporting Russian efforts to bring Riyadh and “moderate Houthis” to the negotiating table to facilitate a peaceful transition.

According to some sources, however, the mission of RussianPMCs is not military in nature at all, but rather commercial: they were deployed in Yemen at the request of  Russian or other foreign companies to secure local infrastructure or oil-related projects. Despite Moscow’s efforts to play a greater role in Yemen, its political and diplomatic influence on the ground is limited. Russia believes that assisting the Saudi-led coalition through the use of PMCs and pursuing a partnership dialogue with the Hadi government will enable it to bolster its presence, while Moscow’s good relations with Tehran allow Russia to put pressure on it to stop arming the Houthis. If Russia succeeds in this, it will strengthen its role as a potential mediator and peacemaker in Yemen.