He believes such attacks illustrate the revival of the "capability and confidence" of al Qaeda in Iraq, buoyed by a Syrian uprising "spearheaded by Sunni militancy."

It stands to reason that the attackers are targeting the government of Iraqi Prime Minister Nuri al-Maliki. The Shiite-dominated government is helping neighboring Iran, the largest Shiite nation in the world and a supporter of the Alawite-dominated Syrian government.

"Al Qaeda in Iraq is becoming less exclusive to Iraq. They are trying to channel energy and piggyback off the Syrian revolution by aiming to merge Iraq and Syria into one theater of sectarian war," said Mardini, adjunct fellow at the Iraq Institute for Strategic Studies in Beirut, Lebanon.

"Given that Maliki is helping Iran prop up the Syrian regime, AQI is advertising their cause and looking to attract the support and resources of militant groups in Syria."

Mardini said Sunni militants are baiting al-Maliki and Shiites to retaliate.

"They're working overtime to plunge Iraq back to sectarian war. But more important than the attacks will be how the Shiites respond. Restraint will be key, but harder to achieve should attacks against Shiites continue. Iraq has already entered the electoral season, where everyone on the political scene fuels the fear factor towards their respective sectarian corners."

It is likely that these attacks aren't going to taper off soon, he said.

"What's going on is a campaign, nothing isolated. The Syrian revolution is a strategic force of instability and will continue to provide both rationale and support to Sunnis trying to fight Shiites anywhere in the region," he said. "Growing Sunni discontent directed towards Maliki's government could be providing more cover for al Qaeda fighters to operate than before."

The Obama administration marks the milestone

U.S. President Barack Obama and Secretary of State Chuck Hagel marked the 10th anniversary of the war's beginning with statements praising the service members who fought in Iraq. Obama honored the more than 1.5 million service members and civilians who served there and the memory of the nearly 4,500 Americans who died there.

"The last of our troops left Iraq with their heads held high in 2011, and the United States continues to work with our Iraqi partners to advance our shared interest in security and peace."

Obama said a strong Post-9/11 GI Bill would help veterans pursue jobs and education.

"We must ensure that the more than 30,000 Americans wounded in Iraq receive the care and benefits they deserve and that we continue to improve treatment for traumatic brain injury and post-traumatic stress disorder."

Hagel and Obama also praised the sacrifices of service members' families.

"Our reflections include the Iraqi people -- the Iraqi soldiers and police officers who died alongside our own, the men and women who were caught in the crossfire, and those who still struggle today to secure and govern their nation," Hagel said. "The Iraqi people will determine the future of Iraq and the United States will continue to support their efforts for a peaceful, secure, free, and prosperous nation."