U.S. State Department spokeswoman Marie Harf explained Monday that the Islamic State of Iraq and Syria, which has marauded through much of the Middle East, leaving thousands dead, won’t be defeated through military force but through responsible governance and better job opportunities.

Harf’s explanation of the Obama administration’s plan for dealing with the deadly ISIS threat came in response to a question from MSNBC’s Chris Matthews.

“How do we stop this? I don’t see it. I see the Shia militias coming out of Baghdad who are all Shia. The Sunnis hate them. The Sunnis are loyal to ISIS rather than going in with the Shia. You’ve got the Kurds, the Jordanian air force and now the Egyptian air force,” Matthews said, adding that “nothing we do right now seems to be directed at stopping this.”

“Well, I think there’s a few stages here. Right now what we’re doing is trying to take their leaders and their fighters off the battlefield in Iraq and Syria. That’s really where they flourish,” Harf responded.

“Are we killing enough of them?” the MSNBC host asked.

“We’re killing a lot of them and we’re going to keep killing more of them. So are the Egyptians, so are the Jordanians. They’re in this fight with us. But we cannot win this war by killing them. We cannot kill our way out of this war. We need in the medium- to longer term to go after the root causes that lead people to join these groups, whether it’s lack of opportunity for jobs,” Harf started in response.

“We’re not going to be able to stop that in our lifetime or fifty lifetimes. There’s always going to be poor people. There’s always going to be poor Muslims, and as long as there are poor Muslims, the trumpet’s blowing and they’ll join. We can’t stop that, can we?” Matthews interjected.

“We can work with countries around the world to help improve their governance. We can help them build their economies so they can have job opportunities for these people,” she continued.

ISIS militants over the weekend released a video purporting to show the beheading of 21 Egyptian Coptic Christians who were captured in Libya, an act of terror that also came with a threat to “conquer Rome.”

“Oh people, recently you have seen us on the hills of Al-Sham and Dabiq’s plain, chopping off the heads that have been carrying the cross for a long time, and today, we are on the south of Rome, on the land of Islam, Libya, sending another message,” a masked ISIS militant said in the video released Sunday.

“All crusaders: Safety for you will be only wishes especially if you are fighting us all together. Therefore we will fight you all together. The sea you have hidden Sheikh Osama bin Laden’s body in, we swear to Allah we will mix it with your blood,” the militant said just before the 21 Christians, each wearing orange jump suits, were beheaded.