BAGHDAD — In the final days before the United States withdrew its troops from Iraq, American intelligence officers worried that a future Sunni insurgency here might be led not by Al Qaeda but by an organization whose leaders are former high-level members of Saddam Hussein’s Baath Party.

Now, after large numbers of Sunni tribesmen clashed with government forces last week, Iraqis of all sects are asking two questions: Is the country headed toward a new civil war? And, if so, will the group of former Baathists lead one side of it?

The group, the Men of the Army of the Naqshbandia Order, commonly known by the initials of its Arabic name, J.R.T.N., has emerged as a potential alternative to Al Qaeda in Mesopotamia for Sunnis who have long felt deeply marginalized under Iraq’s Shiite-led government and are taking up arms once again. Passions were ignited last week after a raid by security forces on a Sunni protest camp in the northern village of Hawija, a stronghold for the group, left dozens dead.

Biding its time, as Al Qaeda has continued to carry out car bombings and suicide attacks, the group has armed itself. It has enlisted recruits from the ranks of Mr. Hussein’s Republican Guard units and devised a well-executed media campaign, with an online magazine, pamphlets and a social media presence, to hone its message that its members are the protectors of Sunni Arab nationalism and guardians against Iranian influence.