WASHINGTON -- The guerrilla war in Iraq has moved steadily beyond the so-called Sunni Triangle and into areas of the country once considered peaceful, a potentially ominous development for security forces trying to restore order in the country.
Since the end of major combat operations on May 1, nearly 40 percent of attacks on US and coalition targets have been outside the Sunni Triangle, home to many remnants of former Iraqi leader Saddam Hussein's regime, according to internal Defense Department reports obtained by the Globe.
The monthly breakdown is classified, but Defense Department officials confirmed that the number of attacks occurring in the far north, south, and far western Iraq -- areas outside the Sunni Triangle, which is immediately north and west of the capital of Baghdad -- has increased in recent months.
This week alone, two US soldiers were shot, dragged, and hit with rocks in the northern city of Mosul and another was killed there yesterday in a rocket attack, adding to growing violence in what had been considered a relatively stable city.
"We have seen an increase," General Richard B. Myers, the Joint Chiefs of Staff chairman, said on Tuesday, referring to the attacks outside the triangle, though he described the increase as modest and insisted that those attacks were probably due to remnants of Saddam Hussein's government.
US forces have stepped up patrols inside the triangle in recent days, hoping to knock out leaders of the insurgency. Myers said military leaders are still examining the rate and location of the attacks outside the triangle to determine how best to contain them.
"We're still looking at what this means in terms of the strategy of the former regime elements that we're up against. How they're tied regionally within Iraq and how they're tied nationwide is to be determined," Myers said. "We don't have as much insight there as we need, and we're working on that insight."
But US intelligence officials said the widening range of attacks could have serious implications for US efforts to quell the guerrilla war, turning citizens from peaceful areas against the coalition forces if it is unable to provide security.
"What I worry about is broader support [among Iraqis] for the insurgent guerrilla activity," said a senior US intelligence official who asked not to be identified. The official added that most of Iraq so far appears to be supportive, or at least tolerant, of the US operation. But "only time will tell."
The Sunni Triangle is home to most of the country's Sunni Muslims, members of Hussein's ethnic group. Southern Iraq, home to the country's majority Shi'ite Muslims, and the Kurdish-dominated north have been more receptive to the US occupation, but guerrilla attacks in those areas have been increasing.
Since May, when major combat operations were declared over, a total of 2,227 guerrilla attacks took place in the Sunni Triangle, according to figures as of the end of last week. The rest of the country has had 1,416 attacks, most of them against occupation forces.
The attacks outside the triangle have included the use of small-arms fire, rocket-propelled grenades, and improvised explosive devices, military officials said. They have targeted US and coalition troops, but also Iraqi security forces and civilians, as well as public infrastructure, such as electrical grids and pipelines.
Military analysts said the widening of the location of attacks is characteristic of a classic guerrilla campaign, in which insurgents seek to destabilize areas of the country that are considered peaceful, slowly expanding the war zone until most of the country fears for its security.
The number of attacks in the southeast sector of the country, where the Shi'ite Muslim and relatively pro-US city of Basra is located, has doubled since August, according to the military's statistics. The exact number of those attacks per month is classified, according to a military official.
Defense Secretary Donald H. Rumsfeld, speaking with reporters on Tuesday, downplayed the significance of the recent spike in attacks in Shi'ite areas.