You are disconnected from the facts.
The CEO of Halliburton move along with a handful of staff. The definition of "headquarters" is where ever the CEO is located (similar to what plane is called "Air Force One"). Hence Dubai is now the "headquarters". It has nothing to do with taxes. The CEO moved because the US has closed off much of the new oil/gas business so the Halliburton CEO moved to be close to the growth area for his business. Good for him!
Hallibutron is registered as a Delaware corp, has express no interest in changing its registered location and continues to file US income taxes on 100% of its worldwide business. All US registered companies file US income taxes for 100% of their worldwide business regardless of where they conduct their business. They can only avoid filing US income taxes if they change their registration to a foreign country, which is (almost?) never done, and physically move 100% of their operations out of the US.
"Halliburton is opening its corporate headquarters in Dubai while maintaining a corporate office in Houston," spokeswoman Cathy Mann said. "The chairman, president and CEO will office from and be based in Dubai to run the company from the UAE."
They are keeping a corporate offices in the US, just like they have corporate offices in other parts of the world for some of their other companies. The company HQ is now run from Dubai, and will lead to them eventually incorporating out side the US so they won't have to pay taxes. Sure the original company might stay incorporated in the US, but they will and already have other companies incorporated outside the US. The contracts will eventually be pushed through these corporate offices out side the US.
Moving to Dubi was just a first step and they will slowly start pushing the business through these other smaller companies of theirs to get out of paying US taxes. They just have too much heat on them right now to make to the big jump.
Just like Halliburton Products and Services Ltd has a office in Tehran and is incorporated in the Cayman Islands so they don't have to pay US taxes.