Dave Gonigam at Desidooru Saloon has just one question today: Why have the Fed and the Treasury now decided to do the right thing and let Lehman Brothers (NYSE:LEH) go into liquidation? Could it be that the federales still don’t know how much they’re on the hook for Fannie Mae (NYSE:FNM) and Freddie Mac (NYSE:FRE)?

Lehman Brothers itself isn’t getting a bailout, but the big-money boys who might wind up as collateral damage can show up at the Fed this morning and borrow at very generous terms.

But the question remains: If Bear Stearns merited $29 billion in federal guarantees to JPMorgan Chase (NYSE:JPM), and if Fannie Mae and Freddie Mac are worth a yet-to-be-determined amount on Uncle Sam’s balance sheet, why is Lehman getting thrown under the proverbial bus?

My hypothesis is that Paulson and Bernanke is still trying to figure out how much they’ll be on the hook for Fannie and Freddie, and thus how much they’re going to have to monetize – that is, print new dollars to make up the difference.

Refusing to take on anything else at the moment has the added benefit (for them) of propping up the dollar and driving down commodities further (oil below $100 this morning? Huh?) before the inevitable inflationary binge.

Source: Why Lehman? Why Now?