Of course it can be said of jails, too, that they try - by punishing the troublesome - to deter others. No doubt, in certain instances this deterrence actually works. But generally speaking it fails conspicuously.
A song must move the story ahead. A song must take the place of dialogue. If a song halts the show, pushes it back, stalls it, the audience won't buy it; they'll be unhappy.
The administration has a disturbing pattern of behavior when it comes to budgeting not only for the ongoing operations in Iraq and Afghanistan but also for military requirements not directly related to these conflicts.

