I believe GP's intent was to point out that a company can get into an agreement with a government (make an offer they can't refuse), but a company cannot get a "region" to sign an agreement/contract with them.
That whole thread is absurd, but if I would have to answer I would say Great Britain is the name of the region/group of islands? Open to be wrong, I know little about the UK
Great Britain is the big island.
UK (United Kingdom of Great Britain and Northern Ireland) is a country consisting of several countries and other territories.