MELISSA BLOCK, host:
During the recent debate over funding the war in Iraq, some of those opposed to a timetable for a troop pullout repeated something President Bush is fond of saying.
President GEORGE W. BUSH: If we do not defeat the terrorists and extremists in Iraq, they won't leave us alone. They will follow us to the United States of America.
BLOCK: That was the president a couple of weeks ago at the White House. Among experts, however, there's widespread skepticism about that assertion, as NPR's David Welna reports.
DAVID WELNA: Shortly before final passage last week of the war spending bill, President Bush says he'll veto, West Virginia Democrat Robert Byrd rose on the Senate floor. Byrd chided the president for trying, in Byrd's words, to scare the pants off the public by suggesting the bill could lead to death and destruction in America.
Senator ROBERT BYRD (Democrat, West Virginia): What utter nonsense. What hogwash.
WELNA: And yet, right after Byrd spoke, Texas Republican Kay Bailey Hutchison repeated the president's claim saying if terrorists are not defeated in Iraq, they will follow U.S. troops home. Utah Republican Orrin Hatch said the same. So did Arizona Republican John McCain. But in South Carolina, where he'd skipped the vote to campaign for president.
Senator JOHN McCAIN (Republican, Arizona): If we withdraw from Iraq, there will be chaos. There will be genocide. They will follow us home and it will be one of the worse challenges America has ever face as a nation and we need to see this nation through.
(Soundbite of applause)
WELNA: Just as McCain fought in Vietnam, so did retired Brigadier General John Johns, a national security expert who helped develop counterinsurgency doctrine there. But Johns considers that they'll-follow-us-home warning propaganda. It's actually leaving American forces in Iraq, he says, that increases the chances of a terrorist attack on the U.S.
Mr. JOHN JOHNS (Retired US Brigadier General): The longer we stay there, the more we're going to create people who will volunteer to come here.
WELNA: That same point was made in the National Intelligence Estimate released last fall, says Senate Intelligence Committee member and Oregon Democrat Ron Wyden.
Senator RON WYDEN (Democrat, Oregon; Senate Intelligence Committee Member): But if the administration feels that the real concern here is the prospect of terrorists coming to the United States or anywhere else. So I have to think about the fact that the National Intelligence Estimate is reporting that their policies are the ones creating more terrorists.
WELNA: But it's not only Liberals like Wyden who questioned whether a U.S. troop pullout from Iraq would be the trigger of a terrorist attack on the American mainland.
Mr. JAMES CARAFANO (Retired US Army Lieutenant Colonel): There's no national security analyst that's really credible who thinks that people are going to come from Iraq and attack the United States, but that's a credible scenario.
WELNA: That's retired Army lieutenant colonel James Carafano, a specialist in international security threats at the conservative Heritage Foundation. Carafano calls asserting that terrorists will follow U.S. troops home naive and poor rhetoric.
Mr. CARAFANO: It's not that if the United States leaves Iraq that terrorists are going to come to the United States. The problem is if the United States leaves Iraq, the problems aren't going to go away. The problems, they're going to go and fester.
WELNA: Still the president's allies in Congress such as South Dakota Republican Senator John Thune insists the Iraq War has kept terrorists at bay.
Senator JOHN THUNE (Republican, South Dakota): We've got them pinned down. I mean, right now they are - the United States military presence is there. And so that's, kind of, where the fight is. And they are where the fight is.
WELNA: That's true, says Paul Pillar, a former deputy CIA counterterrorism chief who now teaches at Georgetown University. But only if you assume there's a fixed number of terrorists out there to bedevil the U.S.
Mr. PAUL PILLAR (Former CIA Official): We are either engaging them or killing them in Iraq, or they're doing something else where we don't have a fixed number, of course. And the longer that we stay engaged in what has become in the eyes of the Islamist jihadists, the biggest and foremost jihad namely Iraq, the more likelihood we will breed even more terrorists.
WELNA: Other experts question whether it's even possible to defeat terrorists in Iraq no matter how long U.S. forces are deployed there. Harvard's Jessica Stern thinks terrorist based there may well pose a threat to the U.S., but she says that's because the invasion of that country beefed up al-Qaida's mobilization strategy.
Ms. JESSICA STERN (Harvard University): I think that we really have created a very dangerous situation, and it will probably get more dangerous for civilians around the globe when U.S. troops leave Iraq. But that will happen whenever we leave Iraq.
WELNA: Still, the president and his allies are not likely to stop repeating that terrorists will follow us out of Iraq. That's because for some it's politically persuasive, says Thomas Sanderson of the nonpartisan Center for Strategic and International Studies.
Mr. THOMAS SANDERSON (Center for Strategic and International Studies): I do think it has the effect of galvanizing support among a percentage of our population, but I think a lot of people won't buy it in the first place. Or number two, assumed that we're already in that pipeline of attacks that the terrorists are planning.
WELNA: One thing all the experts agree on is it's not a question of if such attacks will occur, but when.
David Welna, NPR News, the Capitol.