Volokh, E. (2007). The marines, the coast guard, and the constitution. The Volokh Conspiracy. January 28, 2007. Available online: http://volokh.com/posts/1170035957.shtml.
The tougher conceptual question is whether the Marines can constitutionally be considered part of the constitutionally specified Navy (whether or not they are part of a federal agency labeled the Navy), or must be seen as falling under the constitutional head of “Armies.” In either event they’d be constitutional, but if they are treated under the head of “Armies,” then they’d have to be funded using appropriations that are for no longer than two years; if they are treated under the head of “Navy,” they can be funded under unlimited-length appropriations. Recall that the relevant Congressional powers are:
To raise and support Armies, but no Appropriation of Money to that Use shall be for a longer Term than two Years;
To provide and maintain a Navy.
I don’t know the answer, but I thought I’d flag the question (recognizing that it is of little practical importance, especially these days).
Dr. Volokh then gives speculated on why the Army should be on a shorter lease than the Navy:
My (somewhat vague) recollection is that the constitutional distinction between armies and the navy stems from the fact that Englishmen of the time — including the American variety — saw land-based forces as much more dangerous to domestic liberty than sea-based forces, and sea-based forces as much more important to day-to-day national defense. That’s also why there was lots of concern about a standing army, but not about a standing navy. Modern Marines are in this respect at least potentially more like “armies” than like the “navy”; that’s why the question I pose is theoretically nontrivial.
Is Barnett’s Leviathan an updated version of the Department of the Navy (the few, high-tech, can only be deployed offshore and abroad) while his SysAdmin just an updated version of the Department of the Army (the many, the low tech, deployable at home and abroad). If an Office of Systems Administration is created, would it have to be funded for no more than two years at a time?