Iran

Ever since US President Donald Trump announced in May 2018 that his country would withdraw from the Iran nuclear deal, relations between Washington and Tehran have been sour. In April, the US dispatched the aircraft carrier USS Lincoln to the Gulf region. Secretary of State Mike Pompeo, meanwhile, accused Iran of ratcheting up tensions — without getting into specifics — in the Middle East. Soon thereafter, the US dispatched another warship and a Patriot missile system to the area.

Iran feels acutely threatened by this military presence. The country also finds itself in conflict with Saudi Arabia, with which it vies for regional hegemony. While Tehran backs Syrian dictator Bashar Assad, Riyadh supports the Syrian opposition. Iran and Saudi Arabia also disagree in their stance towards Israel, and Iran has supported rebels fighting against Saudi Arabia in the war in Yemen.

Read more: Iran's Green Movement — why US policies strengthen the regime

This geopolitical context could explain why Iran may be asserting itself vis-a-vis the US. Middle East expert Guido Steinberg of the German Institute for International and Security Affairs (SWP) told DW he is "convinced" Iran is responsible for the recent attack on two oil tankers. He says the way the attacks were carried out make Iran a likely suspect. Iran also "wants to show the US it is able to launch an attack on the oil trade in the Persian Gulf and Strait of Hormuz." It was not an overt attack, but there are clear indications Iran is responsible, Steinberg added. If this is indeed the case, this would signal Iran's ability to disrupt the global oil trade, he said.

Iranian Foreign Minister Mohammad Javad Zarif has dismissed accusations that his country was behind the attacks as "baseless."

The US

US President Trump is not convinced the Iran nuclear deal is having the desired effect. He has often called the deal a "disaster" and has repeatedly claimed the Iranian leadership breached the terms of the agreement. Trump has also claimed that were Iran to theoretically acquire nuclear weapons, the country would aggressively assert its position in the region.

Read more: The Strait of Hormuz — the world's most important oil choke point

Saudi Arabia and Israel, who are close allies of the US, are deeply concerned by this possibility. The US also has a strong interest in avoiding any disruption to the global oil trade. All tankers that take on oil along the eastern coast of the Arabian Peninsula must pass through the Gulf of Oman, a veritable shipping bottleneck. The US is eager to protect this region and ensure the safe passage of these vessels.

Saudi Arabia

Saudi Arabia has long been wary of Iran expanding its influence in the Middle East. Iran has backed militias fighting in countries such as Syria, Iraq and Yemen. Saudi Arabia's de facto leader, Crown Prince Mohammad bin Salman, has attempted to counter Iranian influence by waging a destructive war in Yemen against the country's Houthi rebel insurgency, which is supported by Iran. The war is proving very expensive and deadly, however, and is further damaging the kingdom's international standing, which already took a major hit after the murder of Saudi journalist Jamal Khashoggi last year.

Israel

Israel and Iran have long had an icy relationship. Iran has used the war in Syria to establish a permanent military presence in the country. Hezbollah, which is supported by Iran, has advanced to the Israeli occupied Golan Heights. And Iran's Revolutionary Guard is now stationed a mere 100 kilometers (60 miles) from the Israeli border. Israel, meanwhile, has launched numerous airstrikes against Iranian military positions in Syria.

Like the Trump administration, the leadership in Israel has also spoken out against the Iran nuclear deal.  

Is war looming?

According to the SWP's Kaim, the odds of a direct military confrontation between the US and Iran are slim. However, both sides could trade blows in a one-off type of situation, he explained, for example "when an Iranian speed boat approaches a US cruiser, and a firefight ensues and neither side wants to back down."

"Such a scenario should have us all worried," said Kaim.