I'll be clearer.
If you're hired to work on a on a US Goverment contract, unless the carrying of arms is specifically allowed for your position on that contract, you are not allowed or authorized to carry arms, no matter what.
If its a US Government contract, your employer must follow the statement of work and its restrictions.
So it doesn't matter whether Halliburton / KBR as a firm believes everyone ought to go armed to the teeth or not. They follow the SOW and you follow their rules. Or, they send you home.
If Halliburton hasn't spelled this out yet I'm wondering why they are stringing you along.
Having been in Iraq and seeing the wide variety of intelligence and common sense in civilian contractor employees every company hires (including those hired for armed security or training the INA / IP) I can understand why the Government doesn't want them armed (except for the armed security folks, and some of them shouldn't be allowed a sharp steak knife, let alone an M-4). On the other hand, it is a dangerous place.
But what danger? As the average Halliburton / KBR employee on a US base, the biggest danger is indirect fire (mortars) and IEDs going from one site to another. There have been no insurgent / terrorist "human wave" attacks, etc. Walking around armed won't stop a mortar attack.