Oooops.

BAGHDAD, Jan. 14 — Just days after President Bush unveiled a new war plan calling for more than 20,000 additional American troops in Iraq, the heart of the effort — a major push to secure the capital — faces some of its fiercest resistance from the very people it depends on for success: Iraqi government officials.

American military officials have spent days huddled in meetings with Iraqi officers in a race to turn blueprints drawn up in Washington into a plan that will work on the ground in Baghdad. With the first American and Iraqi units dedicated to the plan due to be in place within weeks, time is short for setting details of what American officers view as the decisive battle of the war.

But the signs so far have unnerved some Americans working on the plan, who have described a web of problems — ranging from a contested chain of command to how to protect American troops deployed in some of Baghdad’s most dangerous districts — that some fear could hobble the effort before it begins.