Republicans reignited a political feud over Iraq, charging that advances by Al-Qaeda-linked forces proved President Barack Obama had squandered American blood in a rush to leave the country. The accusations by prominent Republicans on Capitol Hill coincided with a furor over a new book by former defense secretary Robert Gates that contained blunt criticisms of the president over both the Iraq and Afghan wars. Renewed skirmishes over Iraq were notable, because by most accounts, Obama has won the US political struggle over the conflict, which he built a political career on opposing. The president also followed through on a campaign vow to end US involvement in the war, launched by the George W. Bush administration in 2003. But the president's critics sensed a chance to dent his national security credentials, after the fall to Al-Qaeda-affiliated extremists of key cities where American troops faced pitched battles during the war. Republican House Speaker John Boehner, perhaps trying to capitalize on the White House discomfort over the Gates allegations, took on the president directly over Iraq in his weekly news conference. "Precious blood was spilled and national treasure was expended helping Iraqis remove a brutal dictator and repelling terrorist elements determined to stamp out human freedom and dignity," Boehner said. "That progress is now threatened." Pivoting from the loss of the city of Fallujah, the scene of bitter fighting for US forces, Boehner said Obama had "failed to deliver" by not reaching a deal with Iraq to keep a residual force there after all US troops left in 2011. "We must maintain a long-term commitment to a successful outcome there, and it's time that the president recognize this and get engaged," he said. Boehner said a return of US troops to Iraq -- which the administration has ruled out -- was "not called for at this point" but backed the dispatch of military equipment to Prime Minister Nuri al-Maliki's government. In the Senate, John McCain, a vehement critic of Obama's foreign policy, accused the president of wasting the sacrifice of Americans killed in Fallujah during fierce battles with insurgents over the course of the nine-year Iraq war. "What do we tell these young people and their families?" he asked on the Senate floor. "We have to tell them their sacrifice was squandered by an administration that wanted out and didn't want to remain and consolidate the gains that were made through the sacrifice of American blood and treasure." Obama has repeatedly proclaimed he "ended" the Iraq war, despite rising violence in the country that has killed more than 6,200 people over the last year in car bombings, suicide attacks and other violence. White House spokesman Jay Carney suggested that Boehner's remarks flew in the face of Obama's popular policy to bring US troops home. "I know that Speaker Boehner opposed candidate Obama's promise to end the war in Iraq," said Carney. "I know that. Maybe he still does. Maybe he thinks that American men and women in uniform ought to be fighting today in Anbar province." Democratic Senate Majority Leader Harry Reid complained that Boehner's complaints that Obama was responsible for the fall of Fallujah took "a lot of gall." "I wonder if the speaker wants us to send more troops -- or wants to send troops into Iraq now? " Reid asked. "They're home. The American people are glad." The White House has upped pressure on Maliki this week to embrace reconciliation with Sunni leaders in western Anbar province -- a goal seen as a key step toward ousting Islamic State of Iraq and the Levant fighters in Fallujah who are linked with Al-Qaeda. The Obama administration is speeding up the delivery of missiles and surveillance drones to the Maliki government to help combat the Al-Qaeda resurgence, following pleas for help from Baghdad. But some key players on Capitol Hill are concerned about sending Maliki more offensive weapons including warplanes and helicopters, fearing he could use them on his own domestic opponents as well as Al-Qaeda fighters. On Thursday, Iraqi security forces engaged in heavy fighting with Al-Qaeda-linked militants in the Albubali area, between Ramadi and Fallujah. Fighting erupted near Ramadi on December 30, when security forces cleared a year-old Sunni Arab protest camp. The violence spread to Fallujah, and militants moved in and seized the city and parts of Ramadi after security forces withdrew. Nearly 4,500 troops died in Iraq and tens of thousands more were maimed in a war to oust Saddam Hussein on the grounds of alleged stocks of weapons of mass destruction that were never found.