The Defense Department has promised a swift and "unrelenting" response to the resurgence of al Qaeda in Iraq as the terror faction fights to regain ground lost to U.S. and coalition forces during the war.
On Thursday, leaders of al Qaeda in Iraq (AQI) claimed responsibility for a string of attacks on Monday that left at least 160 dead and over 200 wounded.
The car bombings and attempts to overrun military and government installations in 15 different cities marked the single deadliest day in Iraq since American forces pulled out of the country last December.
Aside from claiming responsibility, Baghdadi also alluded to the group's ambitions to strike targets inside the United States.
“You will soon witness how attacks will resound in the heart of your land, because our war with you has now started," he said.
DOD Press Secretary George Little condemned the violence and said Pentagon officials were working closely with their counterparts in Baghdad to stomp out the group's comeback.
"Make no mistake about it. We are working closely with the Iraqis and with other governments to disrupt, defeat, and dismantle Al Qaida, to include AQI," Little told reporters on Thursday.
"We will be unrelenting as we pursue this enemy," he added.
However, U.S. and Iraqi forces are now facing a reconstituted AQI that not only is gaining ground inside Iraq, but is also spreading inside Syria.
Against the backdrop of the civil war between anti-government rebels and forces loyal to embattled Syrian President Bashar Assad, AQI fighters have begun to flood across the Iraqi border into the country.
While there is no evidence that AQI members were operating with or worked their way into the opposition forces battling to depose Assad, department officials have acknowledged the group's operatives were on the ground inside Syria.
"If the question is, do we believe that AQI has somehow overtaken the opposition or has a significant footprint inside the opposition, we believe the answer is no," Little told reporters on Thursday.
"Are there elements of AQI that might be in Syria trying to do bad things? . . . I can't rule that out entirely," he said.
Monday's brazen attacks capped off a bloody period in postwar Iraq.
In June, a slew of AQI-connected bombings tore through Baghdad and the surrounding area, killing more than 70 people, mostly Iraqi Shi'ites, according to recent reports.
Stuart Bowen, the Pentagon's Special Inspector General for Iraq Reconstruction, told House lawmakers in June that the spike in violence has created a "volatile situation" for American officials.
"The year began violently in January, [but] March ... saw the least violent month since 2003. So it's a very volatile situation," Bowen told members of the House Oversight and Government Reform subcommittee on National Security, Homeland Defense and Foreign Operations.
While the devolving security situation in Iraq has caused concern inside the Pentagon, it remains unclear whether DOD will tackle AQI in the same way it has gone after al Qaeda's Yemeni terror cell.
The department is currently seeking congressional approval for a $75 million counterterrorism package for Yemen.
The proposal, folded into DOD's fiscal 2012 budget request, includes machine guns, sniper rifles, aerial drones, and two new operating bases located near al Qaeda's strongholds in the southern part of the country.
The Senate Armed Services Committee requested another $75 million for counterterror support in Yemen in their $631 billion version of the fiscal year 2013 defense bill.
Little declined to comment on whether the escalating violence in Iraq would prompt DOD to escalate its counterterrorism efforts in the country, along the same lines as ongoing support for Yemen.
"I'm not going to speculate as to what our actions may or may not be with respect to Al Qaida in Iraq," he said. "But let me put it this way — they should not feel like they have any safe harbor."