BAGHDAD, Iraq — The Bush administration’s decision to move thousands of U.S. soldiers into Baghdad to quell sectarian warfare before it explodes into outright civil war underscores a problem that’s hindered the American effort to rebuild Iraq from the beginning: There aren’t enough troops to do the job. Many U.S. officials in Baghdad and in Washington privately concede the point. They say they’ve been forced to shuffle American units from one part of the country to another for at least two years because there haven’t been enough soldiers and Marines to deal simultaneously with Sunni Muslim insurgents and Shiite militias; train Iraqi forces; and secure roads, power lines, border crossings and ammunition dumps. Although military planners are still finalizing the details, as many as 4,000 additional U.S. soldiers are being sent to Baghdad, including two battalions of the Army’s 172nd Stryker Brigade, four or five military police companies from northern Iraq and a field artillery battalion that’s standing in reserve in Kuwait. But when U.S. forces have cracked down in one place, Iraqi insurgents and foreign terrorists have popped up in another. Some towns have been pacified multiple times, only to return to chaos as soon as […]