Jailbreaks are common in Iraq, but the brazen assaults on the prisons at Abu Ghraib and Taji last week are in a class by themselves. The attacks freed perhaps as many as 800 militants, who are now sought by Interpol as a “major threat” to global security. The attacks showed the fearsome and growing strength of Al Qaeda in Iraq, seemingly on the decline only a few years ago. They also raised new questions about the effectiveness of Iraq’s authoritarian prime minister, Nuri Kamal al-Maliki, as well as the stability of Iraq itself.

Al Qaeda in Iraq, an affiliate of Al Qaeda, waged a virulent insurgency that brought the country to the brink of civil war in 2006 and 2007, then suffered major defeats at the hands of Iraqi tribal groups and American troops. It has since rebounded and is believed largely responsible for a surge in daily bombings that have killed an estimated 700 people this month alone.

The Abu Ghraib and Taji operations were synchronized and sophisticated. Western experts told The Times that the militants used mortars to pin down Iraqi forces, sent suicide bombers to penetrate their defenses and followed up with an assault force to free the inmates. A former American ambassador in Baghdad, James Jeffrey, said Iraqi forces performed poorly, suggesting that their skills had deteriorated since American forces departed at the end of 2011.

Oddly, having spent so much money strengthening Iraq’s security forces administration officials have said little, publicly or privately, about why in this case their investment failed so spectacularly.

Iraq is a sovereign country, responsible for its own security. But Iraq might have been better able to repel Al Qaeda if Mr. Maliki and the Americans had worked harder on a deal to keep a token number of troops in the country to continue helping with training and intelligence-gathering. Not surprising, Mr. Maliki’s interest in such an arrangement has grown; Army Special Operations and the C.I.A. reportedly have small units in the country to assist in counterterrorism activities.

Regional volatility, including the Syrian war and Iran, are compounding Iraq’s instability. But the core problem is Mr. Maliki, whose monopoly power and favoritism for his Shiite majority brethren over other groups have inflamed sectarian tensions. In particular, he never made good on promises to reintegrate minority Sunnis, banished from power after Saddam Hussein’s ouster, into the political and economic life of the country. This has made Al Qaeda in Iraq and other insurgents more appealing to resentful Sunnis.

Administration officials, as they should, are working behind the scenes to calm political disputes among Mr. Maliki and Sunni and Kurdish leaders and to create better relations between Iraq and other countries in the region. But absent a complete change of heart and approach by Mr. Maliki, Iraqis and their country will remain dangerously fractured.