The Department of Defense wants a change in the regulations that govern how often reservists can be called when the nation is at war, and war has not officially been declared. Why not just declare war? There are political and practical problems with that. For one thing, there's no country to declare war against.
(Link is not permanent; scroll if necessary to 19 January 05)
I might be reading a different US Constitution than this person, but mine does not stipulate that only a nation-state may be the recipient of US warmaking. I just don't see this as a problem. Declare it and get on with it.