Government contracts are subject to review. There are factors other than $ such as quality, dependability or on time performance. If there were a Government directive to buy from Intel rather than an equivalent vendor there would have to be justification or the awarder would be subject to review and discipline.
Government contracts are a very dirty business, as I well know. GVT pays through the nose because of ridiculous requirements of paperwork and regulations on materials used. Some of the regulations are impossible since specified materials by Country, and age do not exist. A network of procuring companies exist and they double or triple the pricing while certifying that the regulations are met, though the actual manufacturer will not and cannot so certify and for doing the paperwork.
If you are concerned about Intel becoming a monopoly for the Government supply of chips it seems far fetched. The industry is specialized and where a specific chip is being used that will be maintained unless an improved chip is offered. If the GVT needs a special use chip they will work with a vendor to develop it & buy from that vendor.
And political considerations. And lobbying pressure.
I have a three-letter acronym for you: TSA.