Peter Bergen is CNN's national security analyst, a vice president at New America and a professor of practice at Arizona State University. His new book is "Trump and His Generals: The Cost of Chaos." The opinions expressed in this commentary are his own. View more opinion articles at CNN.

(CNN) The significance of Thursday's US strike against Qasem Soleimani cannot be overstated because he ran Iran's military operations across the Middle East.

Iraqi state TV reported Thursday that Soleimani, the commander of Iran's Islamic Revolutionary Guards Corps (IRGC) Quds Force, was killed by rockets hitting his vehicle near Baghdad International Airport. The Pentagon then confirmed it was an American strike ordered by President Donald Trump that killed Soleimani.

Here is how General Joseph Votel, the then-commander of US Central Command that oversees American military operations in the Middle East, explained Soleimani's role in 2018: "Wherever you see Iranian activity, you see Qasem Soleimani, whether it is in Syria, whether it is in Iraq, whether it is in Yemen, he is there and it is the Quds Force, the organization which he leads, that I think is the principal threat as we look at this and the principal ones that are stoking this destabilizing activity."

During the past decade Iran has conducted proxy wars across the Middle East in Iraq, Syria and Yemen and it also controls much of Lebanon through its proxy force there, Hezbollah. Soleimani was in charge of all these operations.

Soleimani also oversaw operations against US servicemen in Iraq by Shia militias in which hundreds of American servicemen were killed following the US invasion of Iraq in 2003. While eager to wind down US wars in the Middle East, President Trump has proven willing to respond militarily when American lives are at risk. He authorized five airstrikes on Sunday against targets in Iraq and Syria that were associated with an Iran-backed militia that the US blamed for a recent attack on an American military base in Iraq that resulted in the death of a US contractor and in which several American servicemen were wounded.

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