File photo of an Iranian Army soldier stands guard on a military speed boat. Ali Mohammad | AFP | Getty Images

When Iran threatens war with the U.S., it's not necessarily talking about war in the conventional sense. But where Tehran can cause damage is an escalation of activities that's likely to send further ripples across regional conflicts and oil markets. The battle of words between Iran and the U.S. hit its latest peak Thursday after the Islamic Republic's top general warned that if President Donald Trump started a war with his country, Iran would end it. "If you begin the war, we will end the war. You know that this war will destroy all that you possess," Major General Qassem Soleimani said from Hamedan, Iran, in a message directed at Trump. It followed several days of back and forth acrimony between Iranian President Hassan Rouhani and Trump and his Secretary of State Mike Pompeo. The open threat was significant, coming from a man who largely operates in the shadows: as the commander of the Quds Force, the elite external branch of Iran's Revolutionary Guard Corps (IRGC), Soleimani is believed to be the single most powerful figure in Iran's entire establishment. To many, he is the most influential operative in the entire Middle East.

Military disadvantage

Regional experts dismiss the likelihood of Iran directly targeting the U.S. or venturing into open warfare. With a spiraling economy and nascent civil unrest at home, not to mention the distinct military and technological advantage of the U.S. and its ally Israel, Tehran is not keen to engage in conventional combat. "The U.S. has a stronger advantage in conventional warfare. Navy to navy, army to army, air force to air force, there is no battle there and I think the Iranians know it," said Aniseh Tabrizi, a Middle East research fellow at the Royal United Services Institute in London. "That is why if there is any scenario in which an escalation would take place, they would go through non-conventional warfare." But Iran has a range of other tools at its disposal to harm U.S. interests, many of which have long been in play and whose deployment is now likely to intensify.

Who is Qassem Soleimani?

Soleimani has run the Quds Force for nearly two decades, conducting covert operations to reshape Middle East dynamics and assert Iranian power and influence.

Iranian Quds Force commander Qassem Soleimani (C) attends Iranian supreme leader Ayatollah Ali Khamenei's (not seen) meeting with the Islamic Revolution Guards Corps in Tehran, Iran. Press Office of Iranian Supreme Leader | Anadolu Agency | Getty Images

During the Iraq war, he commanded groups that killed hundreds of U.S. troops. He continues to arm and assist proxy groups like Hezbollah in Lebanon and Syria and the Popular Mobilization Units in Iraq, and more recently the Houthi rebels in Yemen's civil war. The campaigns serve as part of a wider strategy to counter its regional foe Saudi Arabia. Soleimani "knows he has a range of indirect options to needle U.S. interests across the region," wrote Tobias Schneider, a Middle East analyst at the Berlin-based Global Public Policy Institute, in a recent Twitter post. These include disrupting sea lanes, ballistic missiles against Riyadh, threatening U.S. forces in Iraq and Syria, and meddling in Bahrain through its Shia population, to name a few.

The US and Iran in combat: Deja vu

While not often referenced in present discourse on Iran, the Islamic Republic and Washington have engaged in open combat before. Tehran likely hasn't forgotten the final years of the Iran-Iraq war in the 1980s, when the U.S. military wiped out half the Iranian navy in retaliation for Iran's use of sea-mines, some of which hit an American missile frigate in the Persian Gulf. The 1988 offensive, dubbed Operation Praying Mantis, swiftly destroyed multiple Iranian oil platforms, sea bases and ships. But the current theatrics are defined by asymmetry, wrote Schneider. He argued that there is "very little (the) U.S. can realistically do to roll back Iranian influence," with clearing the Yemeni coast as the most feasible measure. He added that there isn't much sign that Washington's economic pressure on Tehran will actually dampen the IRGC's regional ambitions.

Iranian Revolutionary Guards drive a speedboat in front of an oil tanker at the port of Bandar Abbas. Atta Kenare | AFP | Getty Images

In addition to continued support for its proxy arms in Syria, Lebanon and Iraq, and to a growing extent Yemen, Tehran also financially supports Palestinian Islamic Jihad — the second-largest terrorist group in the Gaza Strip, as designated by the U.S. and the European Union — and has provided lower levels of support for the Taliban in Afghanistan in the form of weapons and some military training. The Quds Force is also active in parts of Syria supporting Bashar Assad's military, and has been the target of Israeli airpower ever since its drones began penetrating Israeli airspace at the start of this year. Iran aims to establish a permanent foothold along the Syrian-Israeli border, something Jerusalem has made clear it will not accept. Iranian-Israeli escalation, and Russia's ability to keep it constrained, could be yet another major game-changer ahead.

Oil chokepoints at risk

Tehran has also threatened to disrupt oil shipping lanes, with officials highlighting their influence over both the Strait of Hormuz — through which 30 percent of the world's oil shipments pass — and the Bab el-Mandeb Strait in the Red Sea, on the opposite side of the Arabian Peninsula.