BAQUBAH, IRAQ — When U.S. forces killed the leader of Al Qaeda in Iraq, Abu Musab Zarqawi, six months ago in a village near here, they hoped security would improve in this strategic province just north of Baghdad.
Instead, security has collapsed in Diyala province, which now ranks as one of Iraq's most troubled regions. Insurgent attacks have more than doubled in the last year. Violence has devastated the provincial police force and brought reconstruction to a virtual standstill.
Assassinations have claimed the lives of mayors, tribal chieftains, police officials and judges, including a Shiite Muslim member of the provincial council who was killed Tuesday. Many government officials here sleep on cots in their offices because driving home is too dangerous.
And Iraqi security forces have been implicated in so many abuses that the U.S. commander here recently gave his Iraqi counterpart an angry lecture, likening the Iraqi troops to an "undisciplined rabble."
U.S. and Iraqi officials interviewed in recent days blamed the sharp downturn on a combination of U.S. neglect and abuses by the Iraqi army. U.S. troops largely disengaged from security here for weeks at a time, they say, handing the reins to Iraqi forces who proved to be abusive and ineffective.
U.S. commanders are attempting a sharp change in strategy, hoping that a classic counterinsurgency campaign, combining reconstruction aid with a more active U.S. presence, can turn the situation around.
For now, insurgents here appear to have gained the upper hand. They demonstrated their freedom of movement last week by barreling a dozen trucks through the streets of Baqubah's Amin neighborhood, shouting militant slogans and brandishing machine guns and shoulder-fired rocket launchers.
The defiant show of force was similar to another insurgent parade caught on video by a U.S. aerial drone in November. Insurgents were seen hauling Shiite families out of their homes and executing them in the streets, U.S. military officials who reviewed the footage said.
Diyala is an area of fertile farmland, abundant water and untapped oil wells stretching north of Baghdad's suburbs and east to the Iranian border. Its population includes all three of Iraq's main religious and ethnic groups.
Of its roughly 1.8 million people, about 55% are Sunni Arabs. But because Sunnis boycotted elections two years ago, Shiites, who make up about one-third of Diyala's population, hold the majority of provincial council seats and control the local security forces. Kurds, mostly in northeastern Diyala, make up about 15%.
