Where US citizens able to travel to Iraq without a passport during the occupation?

Factual Questions
1

Obviously now a government is in place with I am sure immigration controls, what happened in the early days of the USA occupation?

I remember shortly after the invasion during the rebuilding phase companies in the USA had employment ads up for contractors and workers to go from the USA to Iraq. I remember them claiming you did not need a passport to go to Iraq as there were no immigration controls:dubious: Now while I’m guessing the USA government was in charge seems kind of crazy to allow anyone to come to Iraq with no controls, even if it was limited to US citizens.

Was that true?

2

They may have not needed a passport to enter Iraq, but they’d certainly need one to re-enter the US, wouldn’t they?

3

If passport-free entry was limited to US citizens but not to others then there were immigration controls, since establishing whether someone is a US citizen and then admitting or refusing him depending on the answer is a control.

It may well have been the case that the US military administration admitted US citizens without a passport - or, at any rate, did so for US citizens coming to Iraq as employees/contractors/etc of the US military or of approved contractors, or for US citizens coming in through approved routes, or something of the kind.