The "coalition" includes the U.S., Britain, and a bunch of smaller countries whose members make prosecution of the occupation more difficult because U.S. and British troops must protect them.
Wrong answer on two levels.
First, according to troops I've talked to (and embedded journalist accounts) these troops have been invaluable precisely because they free up U.S. troops. For example, Army and Marine troops who are trained for combat have been freed up by El Salvadorans who handled medical duties and mine clearing/UXO duties. BTW, I'll be sure to tell my nephew that the Aussies he worked with killing Al Qaeda needed to be protected. He is going to laugh so hard he'll pee his pants. Can you cite me a source for your assertion?
Second, you are dodging the question. Show me a definition of the word coalition that would allow you to put it in quotes when describing the OIF allies.