Roger Pilon at Cato has some great work on the morality of the national debt and deficit spending:

WSJ article: Is It Immoral To Cut the Budget? (UPDATE: Corrected link–HT: Brian H.)

Cato Forum: The Moral Implications of Deficits, Debt, and the Budget Battles Ahead

Again, the problem I have with the Christian Left is that, with the best of intentions, they assume that gov’t can and will provide efficiently for the poor and elderly. But the money has to come from somewhere. It is actually more moral, Pilon contends, to move from gov’t action which is inherently coërcive, to voluntary action to help the poor. It is also immoral to leave future generations with the burden of debt which will cripple not only the private sector but the gov’t’s ability to provide social (and all other) services.