The home of some of the most ferocious fighting during the U.S. war in Iraq is once again witnessing extreme violence not seen in the country since the last of U.S. troops left two years ago, as al Qaeda insurgents regain control of the city of Fallujah in Anbar Province.

In total, almost a third of the 4,486 U.S. troops killed in Iraq died in Anbar Province. Fallujah was the scene of two significant battles in 2004 - Operation Vigilant Resolve and Operation Phantom Fury – where U.S. military fought against al Qaeda militants.

News of the return of al Qaeda to the city has stirred strong emotions among the men and women who fought in Fallujah, the largest urban military operation involving U.S. troops since the battle for Hue City, Vietnam, in 1968.

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"I'm absolutely pissed; I don't know how to word it really. It's infuriating, it's just like everything we did and what my brothers and I did, was all for naught," former Marine Matthew Brown, 29, from Fayetteville, N.C., told CBS News.

"I feel kind of guilty that we dipped in. We did our jobs, we did it to the best of our abilities but all deployments come to an end," said Todd Bowers, 34, from D.C., a former Marine who was on his second deployment to Iraq when he fought in the surge for Fallujah.

Former Marine Ross Caputi pictured in Fallujah, in 2004. Photo provided by Ross Caputi

Ross Caputi, 29, from Boston, is a former Marine who became an anti-war activist. Caputi believes his fellow Marines lost their lives in vain.

"I feel like my friends' lives were squandered, it didn't really have anything to do with national security, not for the United States or for Iraq," he told CBS News.

"The rhetoric that was given about the siege, that we were fighting against terrorism and we were bringing freedom to Iraqis … and making America a safer place; the second siege of Fallujah did none of that and for all those reasons, my friends died in vain," said Caputi.

Thomas Brennan, a 28-year-old vet from Jacksonville, N.C., who served both in Iraq and Afghanistan and lost over half a dozen friends in his battalion, says his concern about the recent events is for those who lost family members.

"I don't think that a Gold Star mother or a Gold Star widow should ever have to feel like her husband's death was unnecessary or it wasn't for a greater good," said Brennan.

James Sperry, who was 19 years old when he was deployed in 2004, suffered a traumatic brain injury and multiple broken bones when he was struck by a rocket-propelled grenade.

Sperry pictured in Iraq in 2004. Photo provided by James Sperry

"It just shows that what I almost died for - and my life is shortened by my injuries, and I'm already having a lot of issues with my brain - it was almost all done for nothing," said Sperry, 28, from Lebanon, Ill.



