The Ai was not copnstrained in this way. I noticed that the Americans in 1943/44 (can't remember which) had something like 8 invasion forces sitting on the West Coast. Luckily I had absolutely smashed the Allied fleet and so they couldn't hope to invade anywhere.
I also had a bug where I owned all three of the island groups necessary to cut the line of communication with Austraila and yet the status didn't change to orange or count down.