Why don't we cut Federal Spending to 0, fire all the government workers and contractors, have a depression and?

Your plan has flaws, if federal spending were cut to zero, there would be no federal government, as such the states would become independent, the stronger states would seek to consume the weaker states through alliances or conquest, never the less the states would be picked off one by one by foreign influences, that is if chinese tanks aren't rolling down main street first.