As such, demonstrations of force in the straits have little utility for Iran vis-a-vis either the United States or Gulf states. A limited act of coercion typically only makes sense as a signal of one’s willingness to take an even more escalatory step if pushed further. Given just how poorly placed Iran is to make good on such a threat regardless of its intentions, it is unclear that limited coercive steps serve this role.

The Appeal of Catalytic Postures

The apparently puzzling Iranian decision to mine tankers in the gulf of Oman and to carry out similar provocations against shipping in ports in the UAE and oil infrastructure in Saudi Arabia makes more sense if viewed as a means of catalyzing support from states which have an interest in mitigating the maximum pressure strategy and preserving the JCPOA.

In recent months, the E3 have moved to reassure Iran that its legitimate economic interests will be protected from U.S. sanctions if it sticks to the JCPOA. This process culminated in German foreign minister Frank Walter Steinmeier’s recent visit to Tehran to negotiate the institution of INSTEX—a payment mechanism that would allow European companies to trade with Iran sans the dollar. A critical weakness of this approach, however, is that few companies would sacrifice trade with the United States for trade with Iran—and Europena governments cannot compel them to trade in Iran.

Iranian leaders and lawmakers appear frustrated with the lack of progress on this front, however, with Ayatollah Khamenei dismissing the initiative as a “bitter joke.” As such, Iran appears to have pursued a twin-pronged catalytic strategy geared towards prodding the Europeans to up their offer. On the one hand, Iran has gradually resumed the enrichment of uranium—presenting its European partners with an ultimatum to come up with more substantive assurances if they want the deal to survive. The other prong of this approach is the sporadic attacks in the Gulf, which have the potential to cause spikes in oil prices and concomitant uncertainty in European economies. Unlike the United States or the Gulf monarchies, European countries are negatively affected by spikes in oil prices. Moreover, ambiguity with regards to public attribution and pro forma denials of involvement allow Iran to send a tacit message to its partners without visibly backing them into a corner by making an explicit coercive threat that they could not be seen as backing down.

Conclusions: A Bellwether for Regional Power Strategies in an Age of Transatlantic Divisions?

The approach described here is in some ways the most rational use of small and medium-power militaries when faced with a hostile superpower. The likelihood of military overmatch in a direct conflict, even one limited in scope, means that a direct threat vis-a-vis the superpower itself makes little sense in most cases. However even small- and medium-power militaries can serve political ends. Indirect pressure against third-party states, for example, can do a great deal to coalesce political and strategic opposition to the superpower.

A critical point for policymakers, then, is that events in the Strait of Hormuz are reflections of a wider issue—namely the policy divide between the United States and its partners. It is only within the context of substantial policy differences on either side of the Atlantic that Iran’s catalytic strategy makes sense. The assumption on the part of Iran that it has the ability to catalyze the support of Europe vis-a-vis the United States reflects pre-existing divisions between the two parties. As such, directly countering particular threats such as the danger of attacks on tankers is, while necessary, not sufficient. A more critical issue is the strategic opportunity that weaker actors will perceive for as long as they believe that they can leverage competition between major powers to their own ends. Efforts to leverage such divides, likely to become more common in an increasingly multipolar era, could take multiple forms with the development of a nuclear breakout capability or threats to particular chokepoints being particular tactics not to be conflated with the strategy itself. The limited acts of coercion in the Strait of Hormuz, which are likely aimed (albeit not explicitly) at Europe are, therefore, a symptom not a cause.

Dr. Sidharth Kaushal is the Research Fellow for Seapower at the Royal United Services Institute for Defence and Security Studies in London. This first appeared several years ago.