The killing of Iranian Quds Force commander Qassem Soleimani by a United States air raid in Baghdad on Friday has heightened the tension between Washington and Tehran with increased calls in the Iranian capital demanding revenge.

As head of the elite force for more than 20 years, Soleimani was a powerful figure in Iran's strategic objective of defending its interests and expanding its influence across the Middle East.

The Quds Force is the external branch of Iran's Islamic Revolutionary Guard Corps (IRGC) operating in many countries including Iraq, Afghanistan, Lebanon, Syria and Yemen.

The IRGC was founded in the immediate aftermath of the Iranian revolution that toppled the Shah's regime in 1979.

The Quds Force's original objective was to "export" the Iranian revolution but has evolved into projecting Iranian power in the region by providing local groups with weapons and training as well as protecting the country's interests.

"The mission of the Quds Force is similar to that of the CIA. It works on intelligence gathering and is involved in paramilitary operations by training and equipping foreign armed groups," former CIA intelligence officer Luis Rueda, who was the head of Iraq intelligence group during the US occupation, said.

The Quds Force also played a vital role in helping the Syrian government regain control of most of the country from the rebels. It provided arms, military advisers and fighters drawn from the Lebanese Hezbollah group, Iraqi Shia militias and other Shia volunteer fighters.

It was also instrumental in establishing and supporting the Lebanese Hezbollah with financing, training and weapons since its inception in the early 1980s, making it the most powerful non-state military force in the Middle East, according to Iran experts.

Under Soleimani's guidance and support, Hezbollah acquired thousands of long-range missiles, as well as drone and cyberwarfare capabilities.

More recently, the Quds Force was behind the establishing of Iraqi militia group Popular Mobilisation Force (PMF, or Hashd al-Shaabi) which helped defeat the Islamic State of Iraq and Levant (ISIL or ISIS) in Iraq and Syria, also becoming a parallel large military force functioning in large part as an extension of Iran's Quds Force.

Effect of his death

Experts say Soleimani's death is not expected to affect Iran's influence in the region because he was operating as part of a system designed to advance the country's objectives in the Middle East.

Washington-based Iran and South Asia analyst Fatmeh Aman said Soleimani, as important as he was to Iran's strategy in the region, "was just one general from a large military organisation that has the ability to continue after him".

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"Soleimani's death was a big blow but it was not a big blow to the system," said Abas Aslani, a Tehran-based Iran analyst and journalist.

"Soleimani was effective because Iran's strategy in the region was effective," said Rueda.

Reviled figure

Iran will stick to its current strategies in the region despite Soleimani's killing, according to Mahjoob Zweiri, the director of Gulf Studies Center at Qatar University.

He added that while many in the region admire him for his role in helping the Syrian regime, Soleimani remains responsible for the death of tens of thousands of civilians.

In Syria, for example, Zweiri argued that Soleimani was "effectively in charge of the country" and was instrumental in pushing the regime and the Shia militias he deployed to commit "massacres" and "atrocities" against civilians across Syria.

Zweiri added that Soleimani was the key Iranian strategist who helped train the Syrian army, provided weapons and volunteers for the fighting against the rebels that eventually helped the regime regain its footing.

In Iraq, thousands have staged mass protests in the capital, Baghdad, and other cities since October, accusing the government of corruption and of being under Iranian control.

Protesters also burned down offices of Iran-backed militias Soleimani helped set up and train. They were accused of firing live bullets at the protesters.

About 460 people have been killed and 25,000 wounded in protest-related violence over the past three months. Iran-backed militias in Iraq and Lebanon labelled the protesters "western agents".

Aman who is a nonresident senior fellow at the Atlantic Council in Washington pointed out that Soleimani was "unpopular" among the liberals and civil-rights activists because of his role in the crackdown against protesters demanding political and economic reforms in the past decades.

"However, his killing has elevated his status in Iran and rallied the Iranian public behind the government, empowering hardliners and weakening civil society," Aman added.

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