For most Americans, the Iraq War ended when its last troops were withdrawn at the end of 2011. But the violence in the country has barely relented since then, and last week's outbreak of fighting in Fallujah and Ramadi was only the latest eruption of long-lasting sectarian tensions. Plenty of media reports have compared the latest resurgence of al Qaeda-related groups in the al-Anbar region west of Baghdad with the sectarian conflict that erupted in the country in 2006 and 2007. At the time US troops (and money) helped to quell what many feared could develop into a full-scale civil war between Sunnis and Shiites.

Those sectarian tensions remained unresolved when US troops forces pulled out four years later, and last week's violence was triggered by Prime Minister Nouri al-Maliki's decision to break up a year-old protest camp outside al-Anbar capital Ramadi.

Al-Maliki's Shiite-led government has taken a draconian approach to Sunni discontent over the past year, and this, many observers agree, has strengthened the jihadist group known as the Islamic State of Iraq and the Levant (ISIL). ISIL - the latest al Qaeda franchise, also involved in the Syrian conflict across the border - took control of the cities of Fallujah and parts of Ramadi over the weekend.

Memories of Fallujah

Fallujah, in particular, is a name that sparks horrific memories for many American soldiers and Marines. Around a third of the 4,486 US soldiers killed in the Iraq War died in Fallujah's al-Anbar province, with some of the heaviest fighting taking place in this small city 43 miles west of Baghdad. In its report on Sunday about the recent fighting (05.01.2014), the Washington Post reminded its readers that 2004's battle for Fallujah "was the most deadly confrontation of the Iraq war for US forces and some of their bloodiest fighting since the Vietnam War."

But Anthony Cordesman, consultant at the Center for Strategic and International Studies (CSIS) and a frequent advisor to the US State Department, Defense Department, and intelligence community, thinks this emotive factor has been overemphasized by the media. "I don't think you'd find anyone in the US military that sees [Fallujah] as a symbol," he told DW. "And when it comes down to US policy, the concern is not with Fallujah, it is with the broader impact of al Qaeda."

'This is their fight'

On Sunday, US Secretary of State John Kerry had to interrupt his attempts to broker peace between Israel and the Palestinians to field questions on the violence in Iraq. He immediately ruled out the US military's return to help out al-Maliki's government. "We are not, obviously, contemplating returning," he assured reporters in Jerusalem. "This is their fight."

Instead of troops, it emerged on Tuesday (07.01.2014) that the US was fast-tracking deliveries of airplane missiles and surveillance drones to the Iraqi government - despite fears they could be used to suppress the legitimate Sunni opposition in the country - not just ISIL.

President Barack Obama was an opponent of the Iraq War before he took office, and military withdrawal was a key goal of his administration, but the Republican opposition did not shy from blaming the president for the present deterioration. The most vocal critic was veteran Senator John McCain, who released a joint statement with Senator Lindsey Graham on Saturday roundly attacking Obama's Middle East policy.

"While many Iraqis are responsible for this strategic disaster, the administration cannot escape its share of the blame," the statement said. "When President Obama withdrew all US forces … over the objections of our military leaders and commanders on the ground, many of us predicted that the vacuum would be filled by America's enemies. ... Sadly, that reality is now clearer than ever."

"What's sadder still, the thousands of brave Americans who fought, shed their blood, and lost their friends to bring peace to Fallujah and Iraq are now left to wonder whether these sacrifices were in vain," McCain and Graham added.

This last point, argues Cordesman, can be dismissed as a partisan attack by Republicans on Democrats. The real issue is how Obama has dealt with - and helped - al-Maliki. "Any aid to the Iraqi security forces more and more runs the risk of being used to suppress legitimate Sunni opposition, not just extremists," he said.

Botched mission or botched diplomacy?

The obvious omission in the senators' statement is that the Obama administration wanted to keep troops in Iraq longer, but called off a deal - taking the so-called "zero option" - when the Iraqi government refused to grant legal immunity to US soldiers.

Stephen Biddle, defense policy fellow at the Council of Foreign Relations, points out that Obama's initial policy shared McCain's concerns about a hasty withdrawal. "I think the US should have kept a significant troop presence in Iraq, yes," Biddle said. "And the Obama administration thought so, too: that's why they were negotiating. Complete withdrawal was not their aim in the talks."

From 2008 onwards, argues Biddle, US forces were essentially performing a peacekeeping role in Iraq that kept a lid on sectarian tension. "When US troops were withdrawn from Iraq, this stabilizing influence was removed, and the result has been increasing sectarian tension, as you would have seen in the Balkans if peacekeepers there had been withdrawn with comparable speed," he said.

Biddle and Cordesman believe the real - and weightier - criticism behind McCain's statement is not to do with a precipitous troop withdrawal, but a diplomatic failure to keep al-Maliki protecting US interests. "The real failure here was earlier: when we stood back after the 2010 election and did nothing while al-Maliki excluded the Sunni Iraqiya block from the new government and assembled a governing coalition that depended on the Sadrists (the only major part of the Iraqi elite that actually wanted the US to withdraw)," said Biddle.

"We deliberately, as a matter of policy, refused to intervene in government formation and let the Iraqis work it out themselves," he continued. "They did. And the way al-Maliki worked it out suited him ... but failed Iraq - and undermined Western interests, too."

In effect, then, analysts argue, greater diplomatic pressure on Baghdad in 2009 and early 2010 could have stemmed the tensions that erupted so violently last week.