HAL Pilot,
Ad hoc arrangements, pragmatism and curtesy apply in many places, that does not make them mandatory. During the cold war I would have saluted a Russian general, but it would have been as a mark of respect, not because he was entitled. But, as stated
here
"The US rank is held by single track career specialists (ranking between Enlisted Ranks and 2nd Lieutenant)
and have no NATO equivalent.
There are many individuals whose grade gives them the right to use the officers mess. There are also many who hold positions of authority and have serving personnel on their staff. That does not mean that anyone salutes them. I think what is annoying many here is someone indignantly demanding as a right something extended as a curtesy. What normally happens in such circumstances is the curtesy is withdrawn.