"In 2007, I watched a string of vehicles pass from Iran into northern Iraq... the choice was particularly tricky: whether or not to attack a convoy that included Qassem Suleimani...."

"There was good reason to eliminate Suleimani..... But to avoid a firefight, and the contentious politics that would follow, I decided that we should monitor the caravan, not strike immediately.... Suleimani has grown from a military commander into a ghostly puppet master. His brilliance, effectiveness, and commitment to his country have been revered by his allies and denounced by his critics in equal measure. What all seem to agree on, however, is that the humble leader’s steady hand has helped guide Iranian foreign policy for decades—and there is no denying his successes on the battlefield. Suleimani is arguably the most powerful and unconstrained actor in the Middle East today. U.S. defense officials have reported that Suleimani is running the Syrian civil war (via Iran’s local proxies) all on his own.... His staunch defense of Syrian President Bashar al-Assad has effectively halted any progress by the Islamic State and other rebel groups, all but ensuring that Assad remains in power and stays solidly allied to Iran.....  Suleimani is singularly dangerous. He is also singularly positioned to shape the future of the Middle East."

From "Iran’s Deadly Puppet Master/Gen. Stanley McChrystal explains exactly why Qassem Suleimani is so dangerous" in the Winter 2019 issue of Foreign Policy magazine.