What was Iran thinking trying to seize British tanker?

Why would the IRGC, which is already designated a terrorist organization, launch a brazen attack when a British warship was nearby.

British warship arrives at Hamad port ahead of Doha International Maritime Defence Exhibition and Conference, in Doha (photo credit: NASEEM ZEITOON/REUTERS)
British warship arrives at Hamad port ahead of Doha International Maritime Defence Exhibition and Conference, in Doha
Sometimes, Iran acts like it is a playing a complex game of international diplomacy that mixes war threats with diplomatic threats, and that sometimes involves direct attacks designed to show that it means business. Other times, Iran seems to blunder along by doing the most obvious thing that it has said it would do, as if it is just looking for a fight.
Its attempt to seize a British oil tanker appears to fall into the latter category. On the face of it, Iran is carrying out threats it made over the past week to respond to the UK taking over an Iranian oil tanker in Gibraltar.
Less than a day after reports emerged that the US was seeking an international coalition to stop Iranian attacks on tankers in the Gulf of Oman,a number of Iranian fast boats captained by the Islamic Revolutionary Guard Corps (IRGC) approached a British oil tanker. We know this because it was revealed on Wednesday that the boats had sought to intercept the tanker. A British warship, HMS Montrose, warned the Iranians to stay away, and the Iranian boats left.
Case closed? Not really. Why would the IRGC, which is already designated a terrorist organization, launch a brazen attack when a British warship was nearby? Either they are not paying attention, which is unlikely, or they were looking for an incident.
Let’s do the math here. On May 12, four ships were sabotaged in the Gulf of Oman off the coast of the United Arab Emirates (UAE) port of Fujairah. These included ships belonging to Saudi Arabia, the UAE and Norway. Photos of Norwegian tanker Andrea Victory showed a hole in the ship. The US blamed Iran for the incident.
A more serious incident occurred on June 13, when two oil tankers were attacked off the Iranian port of Jask in the Gulf of Oman. An explosion harmed one of them, and a second was later seen with an alleged limpet mine attached to it. Video appeared to show an IRGC fast boat removing the mine. Then on June 20, Iran shot down a US Global Hawk drone, almost resulting in US retaliatory airstrikes. Iran said it could have shot down a second US military plane the same day.
The shoot down and the attacks on the tankers were done with precision. For instance, even though there were 44 crew members on the tankers in June, none of them were harmed. Whoever carried out the attack successfully attached mines so as not to harm the crew. It isn’t clear if Iran thought they would sink one of the ships. Either way, the goal was to show Iran was serious about threatening the Strait of Hormuz.
From June 20 to July 9, things have been relatively quiet on the Iranian front. The US climbed down from talk of war, and Iran’s other actions in Iraq stopped. Only the Iranian-backed Houthis kept up attacks on Saudi Arabia. The US sanctioned Hezbollah members this week, but what really angered Iran was the UK sending Royal Marines to stop an Iranian oil tanker in Gibraltar. Iran warned several times since July 3 that it might take over a British tanker in response.
Oddly, Iranian President Hassan Rouhani appears to have warned of these “consequences” on July 10, after the IRGC had already sent its boats to try to grab the tanker on the same day. Rouhani made a similar decision to travel to Central Asian countries for summits the day after the June 13 attacks, as if the IRGC doesn’t bother to coordinate with his office. Or perhaps the level of coordination is so seamless that he issued the warning with the Iranian fast boats already on their way. But why warn of “consequences” when you’ve already given the green light?
IRAN KNOWS that the incident will fuel US calls for an international force to help protect ships in the Persian Gulf and Gulf of Oman. So this may be an added benefit for Iran, encouraging a coalition to be constructed. But wouldn’t that go against Iran’s stated goal of getting the Europeans to meet its needs regarding the sanctions? The Islamic republic has threatened European countries that it will enrich uranium to 20% and stockpile enriched uranium beyond the 2015 guidelines if the EU doesn’t do more for Iran. It already broke through aspects of the deal this last week.
Iran’s media still speaks of trade relations with the EU. However, Iran’s Tasnim media included the remarks of Rouhani in full, in which he said the UK had created insecurity by intercepting the Iranian ship. Again, it’s not clear why Iran warns of consequences after launching an attempted raid.
The Telegraph reported on July 9 that the British oil tanker British Heritage was “sheltering off the coast of Saudi Arabia amid fears it will be seized by Iran in a tit-for-tat response.” A day later, the report came true as the same ship, British Heritage, was crossing through the Strait of Hormuz and was “approached by five armed IRGC boats.” The Iranians ordered the ship to stop, reports say. A US aircraft monitored the ship from above while the HMS Montrose “aimed its guns on the Iranians and warned them to move away,” according to The Telegraph.
The IRGC isn’t stupid – they could see the Royal Navy frigate. Iran has shown that it monitors US flights out of Gulf countries, including drones. It has radar and other sophisticated equipment. So why would it seek to stop the tanker with the frigate nearby?
The presence of the tanker wasn’t a secret, as media reported it hours before the incident took place. The IRGC was saying “we know your warship is here and we will do this anyway under your noses.” Just to show how brazen Iran can be. To show they are true to their word, choreographing this incident so that they will withdraw, but show they tried.
Did Iran think the Royal Navy would back down? In 2007, Iran kidnapped 15 Royal Navy sailors and held them for almost two weeks. In 2004, Iran also seized six Royal Marines and two British Navy sailors for three days. Five British sailors were also detained in 2009. Those incidents involved Iranian fast boats, but not at attempt to seize a prize as large as a tanker, an act that looks more like piracy in the eyes of international law and the law of the seas.
Iran is brazen. If the reports are accurate, its attempt to harass the tanker was done openly and done with full knowledge of the presence of the British navy to test the UK’s response, and also to see if the US is serious about its international coalition.