The Great Escape - How al Qaeda broke hundreds of bad guys out of the world’s most notorious jail -- and what it means for America.

BAGHDAD — On July 21, the temperature spiked to a sweltering 107 degrees in Baghdad -- brutal heat for the guards and prisoners inside Abu Ghraib's cement confines. Outside, among a patchwork of green farmland and dry brown fields, federal police and army troops -- packing AK-47s, PKC machine guns and sniper rifles -- were positioned throughout the terrain, which is dotted with Sunni farms and villages where insurgents had once launched a guerrilla war against U.S. troops. Within the walls of the infamous prison, the guards -- armed only with pepper spray and clubs -- were the last line of defense from would-be assailants.

At around 9 p.m. that night, as detainees were being counted on the way back to their cells after dinner, the mortars began to fall.

A barrage of more than 40 rounds hit the grounds in rapid succession -- some counted as many as 100 explosions. As guards and detainees scrambled for cover, two car bombs exploded outside, punching a hole in the walls of the massive prison compound.

More than 50 gunmen wearing tribal robes then entered the grounds, wielding pistols, AK-47s, and hand grenades. They had been on the road and in nearby villages, waiting to storm the facility. The power was cut, and the detainees broke out in cries of "God is great."  

The gunmen opened fire on any officer they saw. "The prisoners rioted. Some burned mattresses and clothes, others had stored homemade explosives to hurl at the guards. The infiltrators handed weapons to their jailed comrades. There was screaming and chaos," one of the guards at Abu Ghraib recalled. "We were surrounded."

When the assault ended, 71 prisoners were dead but hundreds of hardened militants had been freed in a stunning attack by al Qaeda's local subsidiary. The exact number is still unclear: The Iraqi government estimated anywhere from 300 to more than 850 detainees, including some arrested by U.S. forces years ago, had been busted out. The fact that the Iraqi security apparatus still does not know exactly how many militants escaped is a stunning admission of incompetence -- and a testament to how badly it was knocked off balance by the assault.

It's not just this one prison break -- there are signs that militants are gaining momentum across the country. Iraq just witnessed its deadliest month since the end of its civil war in 2008: The United Nations announced last week that 1,057 Iraqis had been killed in July.

Al Qaeda's assaults are also becoming more sophisticated. The July 21 attack was coordinated with an assault on Taji Prison, the other main detention facility just north of Baghdad, though no detainees were freed there. Militants have also grown expert at staging coordinated car bombings -- like the wave of attacks on July 29, when 15 car bombs struck Shiite neighborhoods across the country, killing at least 50 people and injuring over 1,000.

The Abu Ghraib prison break was not only a counterterrorism disaster, it laid bare Iraq's political dysfunction. Al Qaeda in Iraq has dashed the hopes of U.S. and Iraqi officials who banked that the 2007-2008 "surge" destroyed the movement, taking advantage of the country's poisonous sectarian politics to regain its strength. Sen. John McCain blamed America's failure to leave a residual U.S. force in the country for the attack. "We won the peace and lost the war. It is really tragic," he said. "And those people who are out of Abu Ghraib now, they are heading right to Syria."

Indeed, Syria's descent into civil war has bolstered al Qaeda's fortunes in the region. The group now identifies itself as the Islamic State of Iraq and the Levant, in a nod to the fact that its cross-border ambitions stretch from Damascus to Baghdad. While al Qaeda has yet to deploy fighters from Syria for attacks in Iraq, according to a former insurgent, some Syrian jihadists have fled into Iraq and received weapons from Sunni tribes.

In addition to using the Syrian conflict to bolster its reputation among disaffected Sunnis, al Qaeda has sought to recruit supporters by exploiting missteps by Iraq's Shiite-led government.   In its statement claiming responsibility for the jail break, the Islamic State of Iraq and the Levant said their operation was carried out as reprisal for the shooting of peaceful Sunni protestors in the northern city of Hawija in April, where security forces killed more than 50 mostly unarmed Sunni protesters.