From: Winnipeg, MB
Section 8.2.1 covers disbanding ground units (p. 184 in the paper manual). As originally written, the base for disbandment must have 100,000 tons of supply OR be one of the national bases. (Vladivostok, Auckland, Sydney, etc.). Updates to the game may have made it possible to use any base with a level 7 or greater port or airfield - not sure about that.
No matter how bad a situation is, you can always make it worse. - Chris Hadfield : An Astronaut's Guide To Life On Earth