For David Bellavia, seeing the images of al-Qaida flags flying over buildings in Fallujah and Ramadi in recent days has been devastating.
"That ground, to me it's hallowed," said Bellavia, who earned a Silver Star for heroism on his 29th birthday fighting in Fallujah as an Army staff sergeant on Nov. 10, 2004.
The images of al-Qaida militants surging back into cities that were secured at an enormous sacrifice has chilled Americans who fought in Iraq. "Most veterans are deeply disappointed that the struggles and the sacrifices they made…have seemingly been for naught," said Peter Mansoor, a retired Army officer who served in Iraq as a brigade commander and on the staff of Gen. David Petraeus.
In a remarkable show of strength, al-Qaida militants last week swept into the two key Sunni cities, seizing police stations and government buildings. On Monday, Iraqi government forces and local tribes continued efforts to expel them from the city.
Fallujah and Ramadi, cities in mostly Sunni Anbar province, are more than obscure towns in Iraq's western desert to veterans of the Iraq War. They represent the darkest days of the U.S.-led war and also where the United States began to turn the tide.
More Americans died in Anbar than any other province.
Fallujah became a symbol of al-Qaida resistance in 2004, leading to a bloody U.S. Marine-led offensive that drove militants out of the city after intense street fighting. More than 80 Americans were killed in combat during the second battle of Fallujah in November and December, 2004.
"How do you tell a parent that, 'Yeah, your son that was killed. … The mission was worth it,'?" Bellavia asked.
"My heart is aching right now," said Jeremiah Workman, who was awarded the second highest valor award, a Navy Cross, for repeatedly entering a house full of dozens of insurgents in Fallujah to recover the bodies of slain Marines. "I think of those Marines and sailors and soldiers that were there and that were lost and that were hurt."
Workman, who left the Marine Corps with a medical retirement after developing post-traumatic stress disorder, said he has been flooded with calls, texts and e-mails from people concerned about him since the news from Iraq.
In Ramadi, the capital of Anbar province, U.S. officers supported Sunni tribal sheiks in a risky gambit that helped turn one of the most violent Iraqi cities into among the most secure. The 2006 tribal revolt, called the Awakening, spread beyond Ramadi and helped turn the tide of war.
Today many of those same tribal leaders are under attack by al-Qaida and are leading the fight to push militants out of Anbar. American officers forged close bonds with tribal sheiks, fighting together to take back Ramadi one block at a time.
"The Anbari leaders that are fighting against al-Qaida today are actually friends of ours," said Marc Chretien, a former State Department official who worked with the tribes in Anbar province for several years.
The recent violence is the result of tensions that have been simmering for years. The civil war in neighboring Syria has attracted foreign fighters and strengthened al-Qaida in the region. The main roads between Syria and Baghdad run through Anbar.
Sunnis in Iraq, meanwhile, have grown increasingly frustrated with the Shiite-dominated government in Baghdad. Al-Qaida, a Sunni terrorist organization has attempted to capitalize on those frustrations.
Some veterans believe the United States did everything in its power to stabilize Iraq before pulling out in 2011.
"In Iraq, one of many things we fought for was to bring stability to a region and give the country of Iraq an opportunity to gain freedom and pursue a democratic government," said Marine Sgt. Maj. Bradley Kasal, who received the Navy Cross for heroism in Fallujah. "And now it's up to them (the Iraqis) to want it bad enough to take what we started and continue to the finish line."
Others blame the Obama administration for not working harder to reach an agreement that would allow U.S. troops to remain beyond 2011.
The administration said it could not win an agreement from the Iraqi government to provide needed legal protections for U.S. troops after 2011.
U.S. forces were seen by Sunnis as an independent institution that would protect them from the excesses of a Shiite-dominated government and would act as a peacekeeping force until a broader reconciliation was achieved.
An Iraqi soldier is seen in silhouette as he guards the main check point of Fallujah in January 2005.
"When you pulled American forces out of there, you lost that glue that was holding things together," Mansoor said.
"What we have here is a failure of the political leadership to follow up on the hard-won military gains," said V.J. Tedesco, a retired Army officer who served as a battalion commander in Ramadi in 2006.
"We've allowed the Shiite-dominated government to act in a way that's prejudicial to minorities, including Sunnis," he said. "On a personal level, that's frustrating."
The Obama administration has said it will support the country but not send troops. "This is a fight that belongs to the Iraqis," Secretary of State John Kerry said.
What haunts many Anbar veterans is a feeling that America abandoned those tribal leaders and sheiks who helped them battle al-Qaida when the war looked nearly hopeless.
"To find them with their backs against the wall and abandoned to their fate just compounds the tragedy," Chretien said.
Contributing: Paul Overberg; David Jackson