I think it mirrored the aims he had in the Gulf of Tonkin Incident; cast American boys as the target of an attack by treacherous foreigners.
And this would justifying a massive, direct US military intervention in a long-standing, far-off conflict.
Except that in this case it would be in theater playing home to most of the world’s energy resources.
Johnson probably figured that the plan would make things simpler in the minds of the credulous US public.
They shot over 800 holes in that thing, but that damned cork just wouldn’t sink —reality intervened, against their plans.
Oddly, Egypt and Israel didn’t have any oil to speak of.
So that theory falls flat with me.
You mileage may vary.