You make it sound like Halliburton is some evil greedy entity that is controlling the US government. There is a well established and closely guarded bidding process which Halliburton won fairly for much of the reconstruction being done in Iraq. It is the American way.
Halliburton employs something like 85,000 Americans. Sure, some of them are greedy and have no respect for the law, just like in every other company or any sampling taken from the street.