A year after Soleimani's killing: The operation, the method, and sanctions

The head of Iran's Revolutionary Guard Corps' foreign operations arm, was carried out by a drone.

The mission was conducted "at the direction of" President Donald Trump, the Pentagon said.

Security sources said 10 people were killed in the strike that hit two vehicles on a road leading to Baghdad international airport.

Soleimani -- who was considered one of Iran's most powerful figures -- was traveling in one of those vehicles.

Abu Mahdi al-Muhandis -- the deputy chief of the Iraqi, largely pro-Iran, paramilitary force Hashed al-Shaabi -- was also killed.

The method used to take out key military figures is more akin to the modus operandi of the Israeli army than US forces, which typically organize their special forces with precision when they seek to take out highly placed figures.

Examples include the raid that killed Osama bin Laden or, more recently, former Islamic State leader Abu Bakr al-Baghdadi.

The United States has closely followed Soleimani's movements over the months before eventually commencing the operation. However, many wonder the timing of the killing. 

The Pentagon said the general had been "actively developing plans to attack American diplomats and service members in Iraq and throughout the region."

Secretary of State Mike Pompeo said Soleimani was planning a "big action" that would have "put dozens if not hundreds of American lives at risk."

"We know it was imminent," Pompeo told CNN. "This was an intelligence-based assessment that drove our decision-making process."

World oil prices jumped by more than four per cent following Soleimani's death, on market fears the killing will crank up tensions in the region.

Iran fired ballistic missiles on US airbases in Iraq targeting Al-Asad and Irbil.

Trump, in a nationally televised address from the White House, said that these missile attacks had not harmed any US troops and the damage was minimal, an outcome he said showed Tehran wanted to de-escalate a standoff.

"All of our soldiers are safe and only minimal damage was sustained at our military bases. Our great American forces are prepared for anything. Iran appears to be standing down, which is a good thing for all parties concerned and a very good thing for the world. No American or Iraqi lives were lost," Trump said.

"The US Administration will impose new sanctions on Iran in response to the attack," Trump said.

However, the tensions continue to remain high between the United States and Iran. 

Iran, even, accidentally shot down Ukraine International Airlines flight 752 carrying 176 passengers. The incident took place shortly after the plane had taken off from the airport in Tehran. It was bound for Kyiv in Ukraine.

Iran had admitted that its forces accidentally shot down the Boeing 737-800 aircraft but the incident heightened tension between US and Iran nonetheless.

"The cabinet approved the provision of $150,000, or the equivalent in euros... for the families and survivors of each of the victims of the Ukrainian plane crash as soon as possible," Iran's presidency said on Wednesday, according to the official IRNA news agency.

"This compensation does not prevent the prosecution of the criminal element of the case before the competent judicial authority," the statement added.

Iranians mourn during the funeral procession of General Qasim Soleimani in his hometown Kerman. Hundreds of thousands of Iranians thronged Tehran's streets on January 6 for the funeral of military commander Qassem Soleimani. Millions of Iranians took part in nationwide events honouring Soleimani, in the lead up to his burial in his home town of Kerman on January 7.