STRATEGIC ASSESSMENT. Since the Hamas attack on Israel on October 7, U.S. and Iranian officials have repeatedly stressed that they want to avoid direct conflict despite backing the warring sides in Gaza. Yet, Iran’s strategy to try to compel the United States to curtail its support for the Israeli war effort has brought the Islamic Republic closer to armed conflict with Washington. Over the past several decades, Iran has cultivated like-minded, mostly Shia Muslim armed groups into a region-wide “axis of resistance” that positions Iran to exert influence anywhere in the region. The alliances enable Iran to act against U.S. and U.S.-aligned interests with a measure of deniability and, in so doing, avoid direct armed conflict with Washington’s far larger and technologically superior armed forces as part of its “unity of fronts” strategy, which Iran is making a geopolitical reality. In the post-October 7 environment, Iran’s support for attacks by its axis proteges – particularly the Houthi movement in Yemen – against Israel, U.S. forces, and commercial shipping has caused U.S. leaders to assess Iran as a threat to vital U.S. interests, including the freedom of navigation. The leaders of both Hezbollah and the Houthis tied recent actions to the war in Gaza, noting that until the conflict between Hamas and Israel was settled, the region would remain volatile.
As of mid-January, Iran appears to be undertaking more direct action to support its allies and thwart U.S. efforts to keep the war limited to Gaza. Iran continues to resupply Hezbollah as fighting on the Israel-Lebanon border escalates, although remaining far short of all-out Israel-Hezbollah war. Iranian leaders have not only applauded but provided direct materiel support to the Houthi movement in Yemen to facilitate its attacks on U.S. and allied naval vessels and commercial shipping in the Red Sea. U.S. officials have repeatedly stated that the Houthi attacks are directly traceable to Iran, insofar that the ballistic and land-attack cruise missiles, armed drones, and other weaponry used by the Houthis were supplied by Iran. Iran reportedly has deployed naval and other forces to help the Houthis identify, and then target for attack, commercial ships financially linked to Israel. In early January, as U.S. and UK leaders threatened to retaliate for Houthi attacks, Iran positioned one of its larger naval vessels (the Alborz) off the Yemen coast as a show of support. Careful to avoid direct involvement, Iran reportedly withdrew the Alborz on the eve of the January 11 U.S. and UK-led strike on 60 Houthi targets in Yemen. The strikes, conducted by U.S. and UK forces with the support of Bahrain, which hosts U.S.-led regional maritime security operations, as well as Australia, Canada, and the Netherlands, came one day after the adoption of U.N. Security Council Resolution 2722 that demanded the Houthis immediately cease attacks on merchant and commercial vessels. The Houthis seem undeterred, however, and yesterday, Houthi militants fired an anti-ship ballistic missile at a Marshall Islands-flagged, U.S.-owned and operated container ship, the M/V Gibraltar Eagle, in the Gulf of Aden. United States Central Command (USCENTCOM) also announced that it shot down an anti-ship cruise missile fired by the Houthis toward the USS Laboon, an American warship operating in the Red Sea.
The U.S.-led decision to strike Houthi targets last week reflected the significant pressure on U.S. leaders to act forcefully after many Houthi attacks, including a widescale Houthi armed drone attack on commercial ships in the Red Sea on January 9. That volley defied a January 3 joint statement by the United States, United Kingdom, and twelve maritime security partner countries warning the Houthis to stand down, although the strikes appear to have failed in deterring the group, whose leaders claim their attacks on naval and commercial ships have attracted new recruits and political support inside Yemen and will not cease until Israel’s war in Gaza comes to an end. Protracted exchanges between the Houthis and the U.S.-led coalition could cause Tehran to take further and more direct steps to support its ally, even though doing so might lead to an unplanned clash with U.S. forces. The January 11 action is also likely to forestall, indefinitely, any chance of achieving a final settlement of the internal conflict in Yemen – a civil war that appeared close to resolution before the October 7 Hamas attack on Israel.
Compounding the potential for U.S.-Iran military engagement, in December and January, Iran used its own forces to conduct attacks that appeared to threaten global commerce. Iran’s assaults could, if continued and escalated, prompt U.S. officials to assert that Iran’s actions impinge on regional freedom of navigation and meet the criteria for an armed response. On December 24, a chemical tanker, the Chem Pluto, was struck by an armed drone in the Indian Ocean during a voyage from Saudi Arabia to India. The strike caused a fire that was extinguished, but no casualties. The U.S. military determined the weapon was launched from Iranian territory. India, which maintains ties to Iran and opposes U.S.-led efforts to pressure Iran economically, sent aircraft and warships to offer assistance to the vessel. On January 10, as U.S.-led military action against the Houthis appeared imminent, Iran seized an oil tanker, the Suez Rajan, in the Gulf of Oman. The ship had earlier been at the center of a U.S.-Iran dispute; U.S. authorities diverted the ship to a U.S. port in 2021 for violating U.S. sanctions on transactions with Iran’s oil sector, and subsequently resold its cargo (1 million barrels of Iranian crude oil). Iran’s capture of the ship seemed intended to send a defiant message to Washington in the context of looming action against Iran’s proteges in Yemen. Over the past decade, Iran has periodically attacked and seized ships in the Persian Gulf in response to U.S. and allied sanctions decisions. However, Tehran’s recent acts against shipping, coming in the context of regional war, have amplified the voices of those Washington officials calling for U.S. military action against Iran itself.
Even though U.S. leaders assess Iran’s actions – both direct and indirect – as a threat to U.S. and broader Western vital interests, the considerations that have always produced caution in Washington on the question of armed conflict with Iran remain. Any military strike on Iran, even if limited, could result in protracted warfare with Tehran that is certain to encompass the entire region. Any U.S. strike on Iranian targets has the potential to cause the still relatively limited Israel-Hezbollah skirmishing to escalate into full-blown war. Iran’s allies in Iraq are nearly certain to support Tehran by attacking U.S. diplomatic facilities in the country, and Iran-aligned militias in Syria will surely escalate attacks on the 950 U.S. military personnel deployed there to combat the Islamic State organization. Any direct conflict with Iran is certain to be costly – militarily, financially, and diplomatically. Iran has developed sophisticated capabilities, particularly armed drones such as those it is supplying to Moscow, that are sure to produce losses of U.S. weaponry and, possibly, military personnel.
Despite the risk perceptions, the United States and Iran remain steadfast in support of their allies and assess that altering their current policies would have adverse political and strategic consequences. Moreover, the diplomatic pathways for de-escalation appear absent. There are currently no talks underway between Iran and the United States or its European allies, either on Iran’s nuclear program, the status of sanctions, or on regional issues. The major Arab states appear focused primarily on shaping the aftermath of the Israel-Hamas war rather than avoiding conflict between the United States and Iran, although the Kingdom of Saudi Arabia has called for “avoiding escalation” following the U.S./UK strike on the Houthis. Global mediators largely lack leverage with either Washington or Tehran. Still, U.S. and Iranian leaders express awareness of the consequence of all-out warfare and appear to try to calibrate their actions to try to avoid it.
