The turmoil in Iraq has made strange bedfellows of two groups that were once at each others’ throats: an al Qaeda offshoot and former Saddam Hussein loyalists.
Both Islamic State in Iraq and al-Sham (ISIS) extremist fighters and former officers of Saddam's Baath Party harbor anger against Prime Minister Nouri al-Maliki's Shiite-led government. This common enemy has forged a tenuous alliance between the two groups and made Iraq's insurgency stronger — ISIS has advanced through Iraq at lightning speed, overtaking major cities and marching toward Baghdad.
But the bond is not expected to last.
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"These guys all hate Shiites. They have different reasons, but they've all been driven together by this sectarianism in the country," said David Schenker, director of the program on Arab politics at the Washington Institute for Near East Policy. But, he said, "Nothing could be further apart than a Baathist and this al Qaeda type of militia. They don't share many values."
For the few thousand ISIS fighters in Iraq, many of whom have come from battlefields in Syria, the goal is to regain Sunni control of Iraq and impose Islamic law.
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The Baathists, who are secular, don't share a vision that includes Islamic law, but do long to bring back the Sunni political dominance that had ruled Iraq since the end of World War I and ended with the collapse of the Saddam's Sunni regime during the U.S. invasion in 2003.
"While the view of Shiites, etc., is shared, I don't know if they can cooperate on the other stuff," Schenker said. "If you think back to the days of Saddam, these Baathists all smoked cigarettes and drank heavily. They don't want to be told that they have to pray five times a day. Baathism is secular Arab nationalism."
And, added Anthony Cordesman, a chair in strategy at the Center for Strategic and International Studies who has traveled frequently to Iraq, "It's not like there is any type of a charismatic leader here unifying Sunni leaders."
While the alliance is predicted to eventually peter out, Iraq can't afford to wait for the bond between the two groups to weaken on its own.
"The more Shiites they kill, the more feuds there will be," said Austin Long, an assistant professor at Columbia University's School of International Public Affairs and a former adviser to the U.S. military. "I don't think we should be waiting it out."
The current round of fighting stems from a centuries-old conflict between the Sunnis and Shiites, which has been aggravated by the rule of al-Maliki, who Sunnis accuse of systematically burning bridges with them instead of building them since he became prime minister in 2006.
"The more Shiites they kill, the more feuds there will be."
"The prime minister, a Shiite, has failed abysmally in creating a formula to share power with the Sunnis, the traditional political masters in Iraq," said Robin Wright, a joint fellow at the U.S. Institute of Peace and the Woodrow Wilson Center, non-partisan institutions.
"What needs to be done is the Maliki government needs to make good on its promises to the Sunni community, to former (local volunteer forces of Sunni citizens) Sons of Iraq, but it may be too little too late," he said. "You already heard promises from the United States and the Iraqi government if you're a Sunni. I'm not sure how likely they are to believe it this time."
Iraqi security forces need to be better equipped to deal with the insurgency too, Long said.
"The fact that you've had entire divisions — tens of thousands of Iraqi troops just sort of melt away around Mosul — that's not just because there were some ex-Baathists with ISIS," he said. "It speaks to the deep impacts of dysfunctional Iraqi politics on security forces."
In a press conference Thursday, President Obama joined the call for Iraq to resolve its political struggles.
"Above all, Iraqi leaders must rise above their differences and come together around a political plan for Iraq's future," he said.