February 16, 2023: Iran’s support of Yemeni Shia rebels suffered another loss when a French warship of the international naval blockade force against Iranian smuggling of weapons intercepted another boat on January 15th. It carried 3,000 assault rifles, 578,000 rounds of ammo and several anti-tank missiles. This follows another interception on January 6th and one in December and one on November 8th. That seizure had two American warships in the Gulf of Oman intercept and searched a fishing boat headed for Yemen from the nearby port of Jask in western Iran. Jask had become the main location where smuggler ships were loaded with hidden cargo for Shia rebels in Yemen. After a search that took a week, the well-hidden cargo of 70 tons of ammonium perchlorate (used for rocket fuel) and 100 tons of urea fertilizer (used for explosives) was found. This was the first time the international naval blockade of Yemen had discovered a smuggler transporting rocket fuel. The Shua rebels were getting this propellant for years and it was unclear how Iran was getting it to Yemen.

Previous cargoes have included Iranian naval mines since 2017. These are a recognized danger to all ships and in early 2020 shipping companies warned their ship captains that naval mines, of the contact type, were floating into the Red Sea from the north Yemen coast. That coast is off the Shia rebel home province of Sadaa and the rebels had been releasing groups of moored and un-moored mines in an effort to disrupt Red Sea shipping traffic to Yemen and Saudi Arabia. The currents generally flow north in this part of the Red Sea, towards the major Saudi Red Sea port and the entrance to the Suez Canal. The Shia rebels drop Iranian moored and unmoored mines into the sea at night. These mines are designed to have their weighted base sink to the bottom of shallow (less than 20 meters) water. A chain is used to keep moored mines near the surface. Some of these contact mines were released to float on the surface while others had their chains break, turning the moored mine into a free floating one. These mines proved most dangerous to Yemeni fishing boats, including the ones Iran used to smuggle weapons in. Dozens of fishermen were killed when their boats hit one of these contact mines. These mines are a danger to blockading warships as well as commercial shipping.

Most commercial shipping is moved in very large ships on which contact mines mostly inflict only minor hull damage. During 2020 there was a major effort to locate and neutralize these free-floating mines. By the end of 2020 over 160 mines were found and neutralized. The rebels continued putting mines in the water during 2021 and the number found and neutralized remained at 2020 levels. After 2020 the mines and bomb boats continued to be used, but in smaller numbers. The use of naval mines has diminished because they are not much of a threat to warships (which are constantly on the lookout for them) and commercial ships that are too big to sink with these mines.

Iran continued to supply the rebels with GPS controlled UAVs that are turned into flying bombs for attacks on targets in Yemen and Saudi Arabia. At times the attacks on Saudi targets are heavy. There was one day when Saudi air defenses detected and destroyed 17 of these UAVs, though the rebels have never used never used swarm attacks to overwhelm air defenses. Such large but uncoordinated attacks often work inside Yemen, but rarely against Saudi targets. Iran smuggles the disassembled UAVs into Yemen on fishing boats and dhows (similar in size but just carrying cargo), where the components are easier to conceal. Some of these have been found. A growing number of smuggler boats were discovered and intercepted after the Americans developed a system for tracking such boats coming out of Iranian ports. The Americans were also obtaining more information from inside Iran about the techniques for hiding smuggled items.

All this costs Iran a lot of money. They have to pay shipyard technicians to modify the boats to carry smuggled cargo. The crews of these boats are also paid a lot for the risks of getting caught and jailed. Iran has been short of cash since economic sanctions were revived in 2020 so the now higher cost of preparing the boats and bonuses for the crews limits the amount of smuggled cargo that reaches the Yemen rebels. That expense was one of the reasons for the nationwide anti-government that began in September 2022 and continue. The IRGC (Islamic Republic Guard Corps), which guard the religious dictatorship that has ruled Iran since the 1980s, also handles Iran’s many foreign wars, which include Yemen, Syria, Lebanon, Gaza and now Ukraine. Iran controls the leadership of the Yemen rebels, in large part because Iran supplies weapons. With that weapons pipeline disrupted during the last three months, the rebels responded by observing a ceasefire with their many opponents.

IRGC leaders were reluctant to give up gains made in Yemen and are unsure when or if they can revive support for the Yemeni Shia because of the growing economic sanctions on Iran as well as the demands of supporting Russia in Ukraine. Because of the sanctions imposed in 2017, the Quds force saw its budget cut by half ever since. This meant major reductions in Quds activities in Iraq, Syria and Lebanon.

Yemen was always the least expensive Quds operation and did not suffer noticeable aid cuts. Yemen was the only IRGC operation that was able to attack arch-enemy Saudi Arabia directly and that counted for something. The Yemen operation was allowed to continue. This was only possible if the smuggled weapons from Iran kept getting through. The Saudis spent several years making deals with tribes in Yemen to half the land route for smuggling. It was up to the naval blockade force to cut the seaborne smugglers and now that link has been cut.

This sharply limits Iran’s ability to directly attack Saudi Arabia by arming Shia rebels in Yemen (over a thousand ballistic missiles and UAVs since 2016). Most of these were aimed at southwestern Saudi Arabia. Less than one percent of those UAVs and missiles hit anything of consequence in Saudi Arabia. Iran sought to carry out a similar campaign against Israel using Iran backed militias in Syria. That has worked so far because Israeli intelligence capabilities and airstrikes have been much more effective in Syria than Saudi efforts in Yemen. This despite the fact that Israel and Saudi Arabia have similar aircraft, smart bombs and air defense systems.

While not as efficient as the Israelis, Saudi pilots and ground forces have gained a lot of practical combat experience in Yemen since 2015. Saudi pilots are much more accurate and surer of themselves than they were during the first two years (2015-16). On the ground the Saudis supply artillery and troops trained to quickly and accurately request and direct air and artillery support. All these ground teams have a year or more of combat experience and it makes a difference. The Yemen ceasefire specifically includes Saudi airpower and artillery. The Yemen rebels are now at a disadvantage and are being pressured to make a peace that the Yemen government and Saudis can live with. Unless the Iranians can revive their smuggling link, the Shia rebels of Yemen will have to take whatever peace deal they can get.