Biden doubted the intelligence that used to justify the killing and warned that it could trigger a war.
On January 3, 2020, Qasem Soleimani, an Iranian major general in the Islamic Revolutionary Guards Corps (IRGC) and commander of the Quds Force, was assassinated in a targeted U.S. drone strike at Baghdad International Airport. President Donald Trump approved the strike. The Associated Press quoting Iraqi officials reported that the airport strike also killed Abu Mahdi al-Muhandis, deputy commander of Iran-backed militias in Iraq known as the Popular Mobilization Forces, and five others, including the PMF's airport protocol officer, Mohammed Reda.
Soleimani was considered the second-most powerful man in Iran after the country's Supreme Leader Ayatollah Khamenei. Touted as a center of power-broking in the region for decades and one of the most influential figures in its foreign and defense policies, Soleimani was designated as a terrorist by the United States in 2005. On his death, Iran's supreme leader vowed 'severe revenge' on those responsible for the top military commander's death.
The Defense Department said it killed Soleimani because he "was actively developing plans to attack American diplomats and service members in Iraq and throughout the region." It also accused Soleimani of approving the attacks on the U.S. Embassy in Baghdad on December 31, 2019.
The attack drew widespread criticism from congressional officials and politicians who feared a forceful Iranian retaliation against American interests in the region, which could spiral into a far larger conflict between the U.S. and Iran, endangering the U.S. troops in Iraq, Syria, and beyond.
The NPR reported that Trump had not sought congressional approval before ordering the strike, which set in motion a controversy regarding the legality of killing an Iranian military leader over Iraqi airspace. The fact that Trump's administration kept changing their stance on the reasoning behind the assassination also raised doubts. Al Jazeera stated that the Trump administration's shifting justifications had been slammed by politicians, including those within the Republican party.
On January 8, 2020, Iran carried out a ballistic missile attack on airbases housing U.S. forces in Iraq in retaliation for the U.S. killing of Soleimani, causing mild traumatic brain injuries to more than 100 US military personnel.
On February 13, 2020, the Senate passed a resolution blocking President Trump from using military force against Iran without congressional authorization. The Washington Post reported eight Republicans joined all Democrats in voting 55 to 45 for the measure despite sharp warnings from Trump that challenging his war powers would 'show weakness' and send 'a very bad signal' to Tehran. Agnes Callamard, United Nations Special Rapporteur on extrajudicial, summary or arbitrary executions, and Director of Columbia University's Global Freedom of Expression project asserted that Soleimani's killing could have been justified under international law only if it had been a response to an 'imminent threat.' But concrete evidence suggesting that had not been provided by the U.S.
The day Soleimani died, Joe Biden tweeted that Soleimani deserved to be brought to justice for his crimes against American troops and thousands of innocents throughout the region. However, he reprimanded the Trump administration, echoing similar fears as other politicians that it could trigger a full-fledged war between the two nations. Calling it an 'escalatory move in an already dangerous region', Biden said that although the administration says its goal is to deter future attacks from Iran, this action almost certainly will have an opposite effect. Biden has also accused Trump of lying about the justification for killing Soleimani. Republicans and the president himself have repeatedly mentioned Soleimani's assassination as an example of his administration's prowess in foreign policy matters.