Yes. They are opposed to it as it is used today. No libertarian believes we need troops in every nation, a navy sailing everywhere, and a war budget greater than nearly all others combined.
And I agree 100% with that, but if you claim to understand why we have a military at all, you cannot claim to not understand why we have to have some secrets.
BTW Snowden’s revelations had nothing to do with the military. May be you are thinking of Chelsea Manning, another hero.
I am glad for Snowden’s revelations, and had he stopped there I would be here joining you cheering for him. But he did not, he stole more than a million documents, many of them related to the military. And he traded them for a place to live to our biggest rival on the planet.