September 22, 2016

TSG IntelBrief: Tensions Escalate Between the U.S. and Iran

• The potential for U.S.-Iran hostilities in the Persian Gulf is increasing as Iran escalates its threats and challenges to U.S. forces there.

• Tensions are escalating in the context of statements by Iran’s Supreme Leader that Iran should develop an ‘offensive’ military capability.

• Saudi Arabia and its Gulf allies—the countries most threatened by Iran’s military capability—benefit from provocative Iranian actions that cause the U.S. to remain wary of Iran.

• In addition to deliberate Iranian provocations, miscalculations and differing interpretations of Iran’s territorial waters could lead to a clash between the U.S. and Iran.


The series of ‘fast intercepts’ of U.S. naval vessels in the Persian Gulf by the Islamic Revolutionary Guard Corps – Navy (IRGC-Navy) in late August were not isolated incidents. On September 4, seven IRGC-Navy fast-attack craft approached a U.S. Navy coastal patrol ship in the central Gulf. The IRGC-Navy vessels did not respond to several U.S. communications, causing the U.S. crew to maneuver to avoid a collision. The tensions nearly escalated into outright hostilities on September 10, when an Iranian air defense station threatened to shoot down two U.S. Navy surveillance aircraft flying over the Strait of Hormuz if they did not change course. The U.S. aircraft continued their patrols and Iran did not attempt to shoot them down, perhaps because the U.S. aircraft was out of range for the Iranian air defense system. Nonetheless, the incident underscored the reality that any Iran-initiated hostility resulting in the loss of U.S. military personnel would almost certainly lead to a significant U.S. response.

The latest confrontations come in the broader context of increasing Iranian assertiveness since the lifting of international sanctions in conjunction with the multilateral nuclear agreement. While attending a military exhibition on September 1, Iran’s Supreme Leader Grand Ayatollah Ali Khamenei said that Iran has an ‘inalienable right’ to develop offensive military capabilities, in addition to defensive. The statement represented a significant deviation from Iran’s often-stated assertion that it’s military is for defensive purposes only. Khamenei’s speech emboldened the IRGC and other hardliners. It also appeared to signal that Iran will not scale back its drive for regional influence in order to achieve better relations with the U.S., Saudi Arabia, or other Gulf states. Whereas the U.S. has the capacity to blunt any Iranian military action, the Gulf states do not. Further aggravating tensions, Khamenei’s statement and Iran’s recent naval provocations come in the wake of rhetorical hostility between Iran and Saudi Arabia over the 2016 Hajj pilgrimage.          

Iranian harassment of U.S. operations in the Gulf has been fueled by the underlying and longstanding disputes between the U.S. and Iran. Despite the multilateral nuclear agreement, Iran’s Supreme Leader and his most ardent followers—including the IRGC—continue to define the U.S. as a hostile power. Iran has never accepted the U.S. military presence in the Gulf as a permanent feature, and views U.S. forces there as part of a broader American effort to intimidate Iran. Neither Iran nor the U.S. are party to the 1982 U.N. Convention on the Law of the Sea, although both countries assert that they broadly accept the Convention’s terms. However, Iran has protested some of the Convention’s provisions, and defines its territorial waters more broadly than is accepted by the U.S. While the U.S. asserts that its forces in the Gulf operate only in waters considered the ‘High Seas’, Iran views those same waters as within its jurisdiction to deny safe passage to potentially hostile military forces. The Iranian definition of its waters explains why the IRGC-Navy has publicly justified its high-speed intercepts of U.S. vessels, asserting that it is acting to prevent ‘enemy incursions’ into Iranian waters. The IRGC belief that it is defending its territorial waters also increases the potential for it to miscalculate the point at which its challenges will provoke an actual armed U.S. response. Based on past experience, the IRGC would likely retaliate for any U.S. strike, almost certainly leading to escalation. 

The Iranian challenges to the U.S. Navy may increase concerns among Saudi Arabia and other Gulf states that Iran is asserting its military power in the Gulf. The Gulf states, already at odds with Iran on several fronts in the region, are in Iran’s direct line of fire. Somewhat paradoxically, however, the Gulf states actually welcome Iran’s provocative naval actions in the Gulf to a degree, as these events reinforce the Gulf states’ position that the multilateral nuclear agreement has not moderated Iran’s regional behavior. The Gulf states also oppose any broad rapprochement between Iran and the U.S. that would grant Iran a ‘seat at the table’ on Gulf security and influence over U.S. regional policies. Some of the Gulf states’ fears have been realized by the U.S. acquiescence to the Russian and Iranian positions on the Syrian conflict, specifically the potential shift in U.S. resolve to oust Syrian President Bashar al-Assad—a key goal for the Gulf states. That goal remains central to the Saudi strategy of weakening the regional influence of Iran and its primary ally, Lebanese Hizballah. The Iranian challenges to the U.S. military presence in the Gulf are likely to recommit the U.S. to its historic alliances with the Gulf states, and dampen U.S. willingness to accommodate Iran’s regional interests.


For tailored research and analysis, please contact: