How might Iran react to a US seizure of its oil tankers?

The Trump administration's new attempts to prevent Iran from exporting fuel to Venezuela, to which they have added a dash of legal and judicial seasoning, could create a new round of escalating tensions between the United States and Iran within weeks of the U.S. presidential election.

After a successful operation by five Iranian tankers to export fuel to Venezuela, four other Iranian tankers are now said to be on their way, reaching their destination in the coming months. However, unlike last time when the U.S. administration failed to intimidate Iran, it is now determined to prevent this second delivery. To this end, the U.S. Department of Justice has announced an order by a federal judge to confiscate the shipments of the four Iranian tankers en route to Venezuela. The order was issued following a request by U.S. prosecutors under the pretext that Iran spends the income from fuel exports to Venezuela on war activities, proliferation of WMDs, military equipment and weapons supporting terrorism, and human rights abuses.

Iranian leaders have called the U.S. move illegal and in line with its policy of maximum pressure to block trade between Iran and Venezuela. There is also the view in Iran that any retreat on the issue, while rewarding Trump, would pave the way for increased pressure on Iran on other issues. This is why the Iranian President, Hassan Rouhani, issued this warning during the dispatch of the first five tankers to Venezuela: “If our tankers in the Caribbean or anywhere in the world face any problems caused by the Americans, they will face problems as well.”

Presently, most reactions among Iranian decision-makers and media are based on retaliation. For instance, Member of the National Security and Foreign Policy Committee of the Parliament, Ebrahim Rezaei, has announced the compilation of a plan in parliament according to which any U.S. action against an Iranian oil tanker or ship anywhere in the world will be met with a quick and appropriate response from the Islamic Republic.

The Javan newspaper affiliated with the Iranian Revolutionary Guard Corps has also reminded Trump of Iran's reaction to the seizure of its oil tanker Grace 1 by the British last year, writing: “Any move to impose physical restrictions on Iranian tankers could lead to a new energy crisis in the world.” The newspaper has not explained the meaning of energy crisis, but it is probably referring to the disruption of vessel traffic in the Strait of Hormuz, which accounts for about 20 percent of the world's energy exports.

An analysis by an IRGC-affiliated think tank also mentions that the U.S. administration’s will to enforce such a ruling is highly unlikely due to its legal invalidity in international waters and concerns about Iran's reciprocal action in the Persian Gulf.

But in another note, the conservative Kayhan newspaper writes that U.S. action is unpredictable and calls internal cohesion and unanimity among authorities in response to U.S. threats the key to victory.

Iran does not appear to be willing to withdraw from sending fuel to Venezuela, as government spokesman Ali Rabiei has said: “U.S. threats will not affect our will to conduct free and legal trade with Venezuela.”

As such, it seems that if the United States decides to seize Iranian oil tankers, there are five options available to Iran in response to U.S. action:

First, the legal and diplomatic response: This is mostly voiced by experts inside Iran who are in favor of filing a complaint with the international legal community as well as the United Nations and begin diplomatic consultations with U.S. partners for the release of its tankers in such an event. This option would be the least dangerous and at the same time probably the most fruitless. The Trump administration has already shown that it does not care much about international law in the process of Iran's appeal to The Hague tribunal and, of course, its withdrawal from the Joint Comprehensive Plan of Action, prioritizing U.S. domestic law — often, in fact national or Trump’s personal interests — over international laws and regulations.

Second, retaliation: Another option preferred by hardliners inside Iran is retaliation; namely, an action similar to the seizure of the British oil tanker Stena Impero last year in retaliation for the seizure of the Iranian tanker Grace 1, or Adrian Darya . This option is certainly risky, and perhaps as the New York Times wrote, Trump is basically looking for such an adventure to pave the way for a military confrontation.

Third, Reducing nuclear commitments: Another option is Iran’s nuclear program, in which the country can take a sensitive step in Western security thinking, such as increasing enrichment levels to more than 20 percent or limiting access by IAEA inspectors. To this end, Deputy Chairman of the National Security Commission of Parliament, Abbas Moghtadaei, has announced discussions on an urgent bill to stop the voluntary implementation of the Additional Protocol by Iran. Given the U.S. policy of maximum pressure and acts of sabotage in Iran in recent weeks, which are said to have been carried out by Israel — as well as the practical passivity of Europeans in supporting the JCPOA — supporters of a withdrawal from the JCPOA and even the Nuclear Non-Proliferation Treaty are increasing every day among some of Iran's elites and the public.

Iran’s non-response to these acts of sabotage may be taken to indicate an equal lack of will to respond to the probable seizure of its oil tankers. But there is an important difference between the two situations. If the tankers are seized, U.S. culpability will be clear, and Iran will have to respond in some way, as it did in the case of Major General Qassem Soleimani’s assassination. Israel, on the other hand, has not accepted responsibility for the acts of sabotage, and Iran may respond proportionally to Israel using similarly underhanded methods in the coming weeks.

Fourth, disruption in the Strait of Hormuz: Another option could be the disruption of maritime traffic in the Strait of Hormuz by increasing military movements and making the international strait insecure. In fact, unlike the second option, Iran would not be taking direct action against the U.S. here. But it would try to force the U.S. to reconsider its actions with a show of power and maneuvers as well as putting pressure on countries benefitting from commerce via the Strait of Hormuz. As Iran's oil sales have dropped to a minimum, the importance of this international waterway has diminished for Iran.

Fifth, proxy forces in the region: Another option that may be more visible is the use of proxy forces supporting Iran in the region, in particular al-Hashd al-Shaabi Popular Mobilization Forces in Iraq and Ansarullah in Yemen to impose costs on the U.S. and its allies. Nevertheless, this option has its own limitations and conditions. The extent of these costs and its success during the prime ministership of Mustafa Al-Kadhimi in Iraq is debatable.

Overall, it seems that the elites, media, and anti-war leaders in the U.S. should take the recent decision by the Trump administration to seize Iranian tankers seriously and prevent an unnecessary crisis for the United States that would only benefit Donald Trump's personal interests.

The seizure of its tankers is not something Iran would remain silent about, especially with the newly elected hardliner parliament which has placed moderates like Rouhani and Zarif in their weakest position in seven years. Therefore, a crisis breaking out between the two countries is very probable.