Americans are rightly outraged over our nation's fiscal situation. The course we're on will lead to public debt that will exceed the size of our entire economy, and a government that will eventually exist to do only two things: fund entitlement programs and make interest payments. Americans may be wondering whether the Greek financial crisis could happen here.

It will—unless we change course. There's a myth that our budget deficit mess sprang into existence at the presidential inauguration on Jan. 20, 2009. But in truth, more...