Withdrawal caused insurgent killings of America's allies in 2004 Anbar

"As the insurgency heated up in early 2004, the Seventh Marine Regiment pulled up stakes and went to fight insurgents in eastern Anbar, leaving the rest of the province in the hands of a battalion of troops.
. . . The consequences were immediate and bloody. Insurgents assumed control of several towns and villages. They tortured and executed police officers, local politicians, friendly tribal leaders and informants. They murdered contractors who had worked with the Americans or the Iraqi government. They tore down American-financed reconstruction projects and in a few cases imposed an extreme version of Islamic law.
. . . Western Iraq became a temporary haven for criminals, terrorists and thousands of local thugs who made up de facto mini-regimes in the absence of a stabilizing force.
. . . The Seventh Marine Regiment pulled up stakes again in November 2004 to join the second fight for Falluja. Conscious of the damage done by the earlier withdrawal, the Marines left behind more troops in an effort to stem the inevitable surge of insurgent and criminal gangs.
. . . Despite this Marine presence, the results were similar."

source
The New York Times. A War That Abhors a Vacuum. December 18, 2006, (op-ed by Ben Connable, Marine Corp major).

posted: tuesday, december 19, 2006, 10:32 AM ET
update: thursday, december 21, 2006, 10:20 AM ET

iraq insurgency withdrawal