Unlike bin Laden or Baghdadi, Soleimani had the power and resources of an entire state at his back—and open support at high levels of the government in the state where he was killed. Both bin Laden and Baghdadi died in hiding and on the run; Soleimani traveled openly in the region where his forces operated. “It’s one thing to kill someone who is considered a terrorist by everyone, including the host country,” Abbas Kadhim, the director of the Iraq Initiative at the Atlantic Council, told us. “It’s another thing to kill someone who is designated as a terrorist by the U.S. but not by the host country—Iraq, in this case.”

“General Soleimani was actively developing plans to attack American diplomats and service members in Iraq and throughout the region,” the Defense Department statement said, declaring Soleimani responsible for a series of attacks on U.S.-led coalition bases over the past several months—including one in late December that killed an American contractor. “We know that the intent of this last attack was, in fact, to kill” Americans, Mark Milley, the chairman of the Joint Chiefs of Staff, said at a press conference yesterday morning, noting that about 100 U.S. military personnel were at the attacked compound in December, in addition to about 200 contractors. “Thirty-one rockets aren’t designed as a warning shot.”

That strike prompted U.S. strikes against five targets in Iraq and Syria where an Iranian-backed militia, Kataib Hezbollah, was operating. The leader of that militia, Abu Mahdi al-Muhandis, who also served as an adviser to Soleimani, was reported killed alongside the Quds Force commander.

Read: Iran loses its indispensable man

Earlier yesterday, Defense Secretary Mark Esper had told reporters that he fully expected Iranian retaliation for the strikes on Kataib Hezbollah, but that the U.S. might act preemptively, and Iran wouldn’t like the results. Now further retaliation from the Iranian side seems all but inevitable, even if what form that will take is unclear. Further U.S. responses may be equally inevitable.

“They will strike back. Just a question of target,” Reuel Marc Gerecht, a senior fellow at the Foundation for Defense of Democracies, which advocates for a hard-line policy toward Iran, told us. “This ends any possibility of nuclear negotiations.”

Phillip Smyth, a fellow at the Washington Institute for Near East Policy who studies Iran’s military forces and their proxies, called the attack on Soleimani the most important decapitation strike America has ever launched, because it’s against a state-backed entity “totally different than ISIS or al-Qaeda.”

“We are talking about the core leadership of a transnational Iranian-led network,” he told us. “They controlled tens of thousands of fighters throughout the region and were old hands—true believers. These were the people who were creating the future for Iran's imperial project.” (The Islamic State is believed to still have perhaps 14,000 to 15,000 fighters in Iraq and Syria, and had no territory left by the time Baghdadi was killed in October.)