Houthi forces have captured the strategic Red Sea port city of Mocha in south-western Yemen, strengthening their position near the Bab el-Mandeb Strait as sources allege Iran’s Islamic Revolutionary Guard Corps (IRGC) directed the group’s recent advance. The United States is providing intelligence and targeting assistance to the Saudi-led coalition backing Yemen’s internationally recognised government, deepening concerns that the conflict is becoming a proxy war.
Control of Mocha gives the Houthis greater influence over the Bab el-Mandeb Strait, a crucial shipping route linking the Red Sea and the Indian Ocean. Disruption to maritime traffic through the strait could place further pressure on global energy supplies following Iran’s blockade of the Strait of Hormuz.
The Iran-US regional conflict has continued for more than six months, during which the Houthis have been viewed as Iranian allies. Houthi forces now appear focused on strengthening and consolidating their control over Bab el-Mandeb, while Saudi-backed Yemeni government forces are conducting operations against them in northern Yemen.
Two Iranian sources told Reuters that Tehran instructed the Houthis last week to intensify attacks against Saudi Arabia, a close US ally. Iran also promised additional funding, weapons and support from senior military officials for the campaign, the sources said.
Iran has publicly described itself as an ally of the Houthis but has denied directing their military operations. Tehran maintains that the Houthis are not Iranian “proxies”.
A regional diplomat briefed from Tehran said several senior IRGC commanders travelled to Yemen after weeks of discussions on military strategy. The commanders were overseeing and directing Houthi attacks targeting Saudi Arabia, the diplomat said.
A third Iranian official said Iran had held several meetings with the Houthis and other allies, but the decision to capture Mocha had been made by the Houthis themselves. The official said the capture nevertheless benefited Iran by increasing upward pressure on oil prices and harming the United States and Saudi Arabia.
Five military officials from Yemen’s Saudi-backed, internationally recognised government said the IRGC had directed the Houthis’ new campaign along the Red Sea coast. The campaign began with heavy rocket fire in the narrow and flat coastal region of Tihama, the officials said.
Yemeni military officials said intercepted communications and accounts from detained Houthi fighters indicated that senior IRGC commander Abdolreza Shahlai was leading the Iranian effort. Iranian sources could not immediately confirm the information, but had previously said the Quds Force officer had spent time in Yemen in recent years.
Iranian sources also said the IRGC remained capable of moving weapons and personnel into and out of Yemen despite air and sea blockades of Houthi-controlled areas. The sources did not provide details on how this was being done.
Ahmed Nagi, Yemen analyst at the International Crisis Group, said the Houthi operation on the western coast had not been prepared suddenly in the past week or month. Nagi described the capture of Mocha as an important milestone in the war and said the Houthis’ evolving military capabilities were mainly due to access to new weapons, received directly from Iran or through smuggling networks.
Nagi also highlighted the Houthis’ use of drones in recent operations.
The United States has stepped up military support for Saudi Arabia as Houthi advances and attacks against the kingdom have increased. Multiple sources familiar with the effort said more than 100 US military advisers were stationed in Saudi Arabia, providing intelligence and targeting assistance to Saudi forces.
A US official said the total number of US troops in Saudi Arabia was about 200.
CNN, citing sources, reported that the US personnel were working as part of a new joint force command established in recent weeks amid signs that Iran was increasing support for Houthi attacks against Saudi Arabia. Five sources familiar with the operation confirmed to CNN the presence of US forces in Saudi Arabia and their role in assisting the effort.
A US official said Washington had helped Saudi Arabia use a targeting system that allows military officials to see battlefield developments in real time. The official compared the system with the Pentagon’s Maven system.
Another source familiar with the ongoing US-Saudi cooperation said Washington was providing geospatial targeting support for Saudi strikes against the Houthis. The source said strict restrictions currently applied to US assistance.
The United States is sharing intelligence with Saudi Arabia, as it does routinely, but US forces are not directly participating in attacks. Washington is also not refuelling Saudi warplanes or providing other operational support, unlike during previous fighting against the Houthis.
One source said the central objective of the current effort was to ensure Saudi military operations were conducted in an orderly and professional manner.
All sources described the initiative as an expansion of existing US cooperation and training programmes with Saudi Arabia. A US Department of Defense official said: “As a matter of practice, we do not comment on intelligence matters.”
The latest US support comes as fighting on the Arabian Peninsula has intensified amid the Houthi advance. Recent clashes may have reached their most intense level since 2022, when a fragile ceasefire took effect between the Houthis and the Saudi-backed Yemeni government.
Yemen has remained effectively divided despite the ceasefire.
US officials fear that escalating Houthi attacks could open a second front in the Iran-US war. US officials believe several hundred IRGC officers are currently in Yemen, working with the Houthis with the ultimate objective of closing the Bab el-Mandeb Strait.
Closure of Bab el-Mandeb could have major consequences for global trade and energy supplies because the waterway connects the Red Sea to the Indian Ocean. CNN previously reported that Iran had planned an economic “nuclear option” if talks with the United States failed, including closing Bab el-Mandeb through the Houthis.
US Secretary of State Marco Rubio indicated at the start of the week that intelligence pointed to an IRGC presence in Yemen. According to a US official, Rubio said Iran was involved in recent Houthi attacks targeting Saudi energy infrastructure.
Yemen’s government sought additional Saudi air support and other assistance when the Houthis began advancing towards Mocha last week, according to two Yemeni officials. The officials said the government requested Saudi air strikes on Houthi-controlled areas, including Sanaa, regarded as the Houthis’ main stronghold, and strategically important sites such as oil storage facilities.
Saudi Arabia decided instead to provide logistics, weapons and intelligence support rather than launch a major air campaign. Limited air strikes were carried out, but were largely concentrated on battlefields in the northern provinces of Al Jawf and Marib, which Yemen’s government considered comparatively less important.
Yemeni officials assessed that Riyadh was seeking to avoid major escalation because of concerns that it could provoke larger Houthi drone attacks. Reuters contacted Saudi officials for comment on why Riyadh had focused more heavily on northern battlefields rather than the Red Sea coast and other key Houthi targets, but they did not immediately respond.
Saudi Arabia was initially reluctant to become deeply involved in the US war against Iran. Riyadh had also refused to support an early US effort to escort commercial ships damaged in the war with Iran earlier this summer.
Increasingly aggressive Houthi attacks have raised fears of a second war front involving the United States and Saudi Arabia. US forces are already under significant strain from the conflict in Iran, which has lasted more than six months, with American personnel in the Middle East repeatedly facing missile and drone attacks.
Concerns have also grown over lengthy deployments and ammunition stockpiles.
US military operations have largely focused on the Strait of Hormuz, where American forces have struck Iranian targets, escorted commercial vessels and maintained a naval blockade of Iranian ports.
US military officials remain deeply cautious about becoming too closely associated with Saudi Arabia’s anti-Houthi campaign, particularly because of the risk of civilian casualties if strikes go wrong. A US official said such incidents had occurred in the past.
“This is not like the old days,” another source involved in the effort said.
US forces are also weighing past experience in supporting Saudi Arabia. Targeting assistance provided to Saudi Arabia during the Obama administration and the first Trump administration generated major controversy, with critics alleging that the support contributed to high civilian casualties.
During the second Trump administration, the United States conducted several months of operations against the Houthis in Yemen before ending the campaign through a sudden ceasefire agreement.
General Dan Caine, chairman of the Joint Chiefs of Staff, pushed for a swift end to that campaign after becoming President Trump’s top military adviser. Caine was concerned that the operation lacked a clear exit strategy.
Assessing Yemen’s overall military situation remains difficult because major fighting was largely suspended for several years after the 2022 ceasefire. Iran and Saudi Arabia have both invested in their respective allied forces in Yemen, but the coalition supporting the Yemeni government has been weakened by internal divisions.
Ahmed Nagi said previous rounds of fighting in Tihama had seen rapid advances followed by quick retreats. Nagi said it remained unclear whether Saudi-backed forces could easily drive the Houthis from the area this time.
Government-aligned forces could make some gains if they received the necessary support from Saudi Arabia, Nagi said, but added that this could be difficult.
The capture of Mocha and the Houthis’ rapid advance along the Tihama coast have pushed Yemen’s long-divided conflict into a new phase. Houthi forces are tightening their control over Bab el-Mandeb, while Saudi Arabia and the United States are preparing in a limited way to halt their advance.
A wider conflict centred on both the Strait of Hormuz and Bab el-Mandeb could place major pressure not only on Yemen and Saudi Arabia, but also on global energy supplies and international maritime trade.