Many monumental errors and misjudgments contributed to the acute financial turmoil in which we now find ourselves. Nevertheless, the vast accumulation of toxic mortgage debt that poisoned the global financial system was driven by the aggressive buying of subprime and Alt-A mortgages, and mortgage-backed securities, by Fannie Mae and Freddie Mac. The poor choices of these two government-sponsored enterprises (GSEs) -- and their sponsors in Washington -- are largely to blame for our current mess.

How did we get here? Let's review:...