Q: WHY IS THIS HAPPENING NOW?

A: The group, the Islamic State of Iraq and the Levant, is taking advantage of two trends: growing discontent among Iraq’s minority Sunnis toward Prime Minister Nouri al-Maliki’s Shiite-led government, which they accuse of discrimination; and the increasingly sectarian dimension of the Syrian civil war, as mostly Sunni rebels fight to oust a regime dominated by members of a Shiite sect. Taking advantage of the breakdown of state authority, militant fighters easily cross the border. The Iraqi territory recently seized by militants is populated overwhelmingly by Sunnis, many of whom, at least for now, may see al-Maliki as more of a threat than the Islamic State.

Q: WILL IRAQ BE A DIVIDED STATE?

A: The recent developments have renewed the possibility, much discussed during the war a decade ago, that Iraq be divided into three separate regions or even nations – the mostly Shiite section, made up of Baghdad and much of the south and east bordering Iran; a Sunni area, comprised of western Iraq and parts of the north; and a Kurdish zone, also in the north and including the cities of Irbil and Kirkuk, which Saddam tried to populate with Arabs.

Q: WHY WON’T THE ARMY FIGHT?

A: Corruption and sectarianism are widespread problems in the security forces, with little sense of professionalism or loyalty to the Baghdad government – even though Shiites make up most of the army. Also, Islamic militants are terrorizing Sunni soldiers and police, in at least one case beheading an officer and then distributing a video of the attack.

Q: HOW HAVE THE REBELS BEEN ABLE TO MOVE SO QUICKLY?

A: The Islamic State commands between 7,000 and 10,000 fighters, according to U.S. intelligence officials. The group’s military strategy is still somewhat of a mystery, but the extremists have cunningly crafted their tactics and message to meet local considerations. In Syria, they are quite open about their ideology and goals, imposing their strict brand of Islamic law, banning music and executing people in the main square of Raqqa, which they control. In Iraq, they focus on portraying themselves as the protectors of the Sunni community and have at least so far overlooked some practices they consider forbidden.

— The Associated Press