If you have any doubts about this assertion, just take a close look at all the libertarian books that have been published in the last five years. Or watch the speeches and interviews that libertarians deliver. Or the many libertarian articles, both on the Internet and the mainstream press.
You will notice that virtually none of them ever call for dismantling the Pentagon, the military-industrial complex, the CIA, and the NSA, all of which are the principal components of America's national-security state.
Oh sure, they'll call for ending America's "endless wars." They will wax eloquent about the horrible consequences of foreign interventionism. They call for "bringing the troops home," just as some conservatives and progressives do.
But they never call for discharging those troops when those endless wars are ended and those troops are brought home. They want them to remain on active duty here in the United States. They express no objection to a massive well-armed garrison state here at home. Indeed, when was the last time you read any article written by a libertarian or heard a speech by a libertarian calling for the closure of domestic military bases?