“National Security” is such a Shibboleth.
What would be revealed? “We have some really cool weapons”. Oooooooooooh! If people found out, we’d be in great danger!!!!!!
What??
The dirty little secret is that they have no clue what this stuff is.
Governments do not like to admit they have failed at providing national security.
Taxpayers might get the crazy idea of keeping their own money instead of sharing with useless bureaucracies.