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The U.S. and its allies have killed many Islamic State militants and, for now, stopped their plan to build a state in Syria and Iraq. But what has happened to the surviving members of ISIS? NPR's Greg Myre takes a look.
GREG MYRE, BYLINE: The Islamic State doesn't control any cities. Its ranks are decimated. Survivors have scattered. Yet ISIS still has militants with weapons and plans for renewed mayhem.
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JIM MATTIS: We have repeatedly said in this room, the war is not over.
MYRE: Defense Secretary Jim Mattis, speaking here at the Pentagon, says U.S. forces are still tracking down small pockets of ISIS fighters in Iraq.
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MATTIS: It may be a dozen guys who finally find each other, you know, and they get together, and they start living in one house, and they start licking their wounds and think, what can we do? So what we want to do is drive this down to a point it can be handled by local authorities, by police and that sort of thing.
MYRE: And in Syria, where the U.S. and its allies have pounded the militants in the eastern part of the country, some are fleeing westward. The ISIS fighters apparently believe their chances of survival are better in areas controlled by their other enemy, Syrian President Bashar Assad and his army. So how many Islamic fighters are there? It's always been a guesstimate. When ISIS was at its peak three years ago, the CIA said it had as many as 31,000 fighters. The U.S. military now thinks fewer than 1,000 are left in areas where the American coalition is operating.
DANIEL BYMAN: The Islamic State fighters in a number of places - Mosul, Raqqa, many others - put up very fierce fighting, and thousands of their fighters died in these battles.
MYRE: Daniel Byman of Georgetown University closely follows ISIS. He puts the surviving ISIS members in a couple other categories with intentions that vary.
BYMAN: Another group of fighters probably tries to flee or blend in locally. And then there's a third category that's either trying to hide out in places in Iraq or Syria or who have tried to make their way outside the country.
MYRE: Many foreign fighters came from Europe. And Nick Rasmussen, who just stepped down as the head of the U.S. National Counterterrorism Center, says European countries have been bracing for returning militants. However...
NICHOLAS RASMUSSEN: The problem that we envisioned perhaps a few years ago of thousands and thousands of foreign fighters departing the conflict zone once the war started to subside - that's what we anticipated happening, and it's not happening in those numbers.
MYRE: So most of this news sounds pretty good. ISIS has no safe haven. Its fighters are on the run, and they aren't escaping abroad in large numbers. But remember this. The forerunner of ISIS was al-Qaida in Iraq. The U.S. and its allies dismantled that group a decade ago. It then reemerged as ISIS, stronger than ever, as conditions proved more favorable. This included the chaotic Arab uprisings of 2011 and the U.S. military withdrawal from Iraq that same year. This lesson isn't lost on ISIS.
GAYLE TZEMACH LEMMON: It is far easier to kill a terrorist than to slay an ideology, and that has always vexed the folks who are prosecuting the campaign.
MYRE: Gayle Tzemach Lemmon is with the Council on Foreign Relations. The U.S. has a good record when it comes to winning battles in the Middle East. What's hard, she says, is the aftermath.
LEMMON: And as long as the ground is still ripe for insurgency, it's very hard to keep a war ended. And the truth is, no one really wants to pay for the rebuilding. Nation building is a 14-letter word that has become a four-letter word.
MYRE: The Islamic State stresses that it's waging a long war, and the hardcore leadership sees the recent setbacks as something that can be reversed. Greg Myre, NPR News, Washington.