Yemen's Zaidi al-Houthi rebels recently have been able to expand their control across Yemen's northern provinces. This expansion comes as Yemeni President Ali Abdullah Saleh's forces are concentrating on stifling anti-regime protesters and battling defected Brig. Gen. Ali Mohsen al-Ahmar's forces in Sanaa province and central Yemen — all while dedicating resources to the southern provinces, where battles with al Qaeda in the Arabian Peninsula (AQAP) and tribal militias continue. The next goal for the al-Houthi expansion appears to be Midi, a small town with access to the Red Sea. Midi is strategically valuable for gaining access to arms and resources, as the al-Houthis' indigenous resources and the general availability of arms in Yemen have been insufficient for the al-Houthis to gain the autonomy they had before Saleh came to power. Midi's importance was evident in November 2009, when Saudi Arabia's navy blockaded northern Yemen's Red Sea coast for fear that the al-Houthis were being supplied through Midi and Salif. (click here to enlarge image) STRATFOR sources have said the al-Houthis have gained tactical control of territory in Yemen's Saada and al-Jawf provinces, both of which border Saudi Arabia. This is an important development because Saudi Arabia could feel forced to respond militarily if the rebels threaten its provinces of Jizan and Najran again. Sources have also said the al-Houthis are moving toward Midi. Reports in The Yemen Observer have cited residents of Hajja province as saying the al-Houthis are seizing towns and villages in the province, including the mountainous Kuhlan al Sharaf district, to secure an open route to the Red Sea port. Before unrest ensued elsewhere in the country at the beginning of the year, the rebels' expansion into the northern provinces was much more difficult, as the Yemeni regime was able to maintain pressure on the al-Houthis and provide financing and resources to various tribes and militant groups to keep the al-Houthis in check. For example, in Hajja province, Saleh's regime supported such tribal groups as the Kushar and Aahim, according to The Yemen Observer. But now that the regime's focus and resources have shifted to central and southern Yemen, the tribes that once resisted the al-Houthi expansion are much weaker. In al-Jawf province, the Yemeni and Saudi regimes gave various tribal forces resources to attack the al-Houthis. However, it is clear that such efforts have been less effective of late since the al-Houthis have been able to exploit Sanaa and, given Riyadh's distractions with unrest at home and elsewhere in Bahrain, expand their area of influence.

The Strategic Significance of Red Sea Ports

The acquisition and control of Midi has been one of the al-Houthis' main strategic goals. The port does not hold great economic significance for Yemen; it is very small, and it is unclear if it can accommodate large container ships. However, the port has been the rebels' main access point to small arms, funding and possibly foreign advisers. In 2009, Midi — along with the port in Salif — was thought to facilitate the smuggling of weapons and materials to the rebels. Midi in particular is known as an entry point for illegal immigrants being smuggled into Yemen. In November 2009, Yemeni authorities arrested 30 illegal Somali migrants believed to have been smuggled through the port city; these immigrants allegedly were deployed to take up arms with the al-Houthis. Some could have been on their way elsewhere, as Yemen has served as an intermediary destination for African migrants on their way to jobs in Saudi Arabia. If the al-Houthis could gain full control of Midi or Salif, it would be easier for them to acquire weapons and resources to secure and defend the provinces where they have established influence. It could also give them control of some amount of trade, which would give them tax revenue to support their attempts at autonomy. But Riyadh fears that any success by the al-Houthis in Yemen would inspire the group's fellow Zaidis across the border; if the al-Houthis can secure a path to these ports, the Saudis likely would intervene. In fact, Saudi Arabia intervened on a previous occasion in August 2009 during an incident known as the al-Houthi rebellion in which the Yemeni regime was already cracking down on the rebels. The al-Houthis were gaining control of areas that Riyadh considered dangerously close to the border with the Saudi provinces of Najran and Jizan. By November the Saudis staged a small naval blockade with an emphasis on aerial bombardments and artillery fire targeting rebel positions to prevent the al-Houthis from gaining access to the Red Sea.

Struggle for Power in the Persian Gulf

The Saudis fear that Iran is supporting the al-Houthis in a proxy battle between the Arab and Persian powers, who are continuing their geopolitical competition over the Middle East. Unconfirmed reports from STRATFOR sources indicate that during the 2009 al-Houthi rebellion, Iran's Islamic Revolutionary Guard Corps (IRGC) trained the al-Houthis in producing improvised explosive devices and even sent supplies along a route via Eritrea's Assab Harbor. According to the sources, IRGC officers bought and transported weapons in Somalia and Eritrea and shipped them to Yemen's Salif port, where the supplies then passed through Hajja and Huth in northern Yemen before reaching Saada. The IRGC also reportedly used a more traditional route from Assab Harbor along the heel of the Arabian Peninsula in the Gulf of Aden, then to Shaqra in southern Yemen and on to Marib, then Baraqish and finally to the mountains in Saada. The al-Houthi expansion is occurring as Saudi Arabia views the United States as struggling to form a coherent containment strategy against Iran, especially as the deadline looms for U.S. forces to withdraw from neighboring Iraq. In addition, Saudi Arabia has been trying to clamp down on Shiite unrest in Bahrain while attempting to keep Iranian clandestine activity on the eastern side of the Arabian Peninsula at bay. Saudi Arabia has a similar interest in keeping potential Iranian influence in Yemen away from the southern Saudi border. Although the Iranians would like to get involved in such conflicts, their involvement with the al-Houthis would be limited, due to sectarian disagreements and the difficulty of accessing al-Houthi territory. Indeed, the al-Houthis likewise face geographic challenges as they attempt to gain control along the coast. If successful, they would be more vulnerable to conventional fighting — airstrikes and artillery — and would not have the advantages of guerrilla tactics that they have in the mountains at present. These challenges will be particularly difficult as the rebels move through Hajja, a majority Sunni Arab province where they likely will face resistance before they can control either port. Meanwhile, Saleh's forces will be operating under heavy constraints, as they remain focused on quashing other unrest and fighting AQAP. With Saleh's regime preoccupied, if the al-Houthis continue expanding to the southwest and securing a path to Midi, it will become increasingly likely that the Saudis will move to crush the possibility of a strengthening al-Houthi force that could threaten Saudi stability.