Not long after 9/11, the Air Force went looking for a new fleet of aircraft.  The service drew up a plan to lease 100 aerial-refueling tankers from Boeing, saying it had an urgent need to replace its aging, Eisenhower-era KC-135 aircraft.

The Air Force planned to award a multibillion-dollar contract for a new tanker, based on the Boeing 767,  as a “sole source” — meaning there would be no opportunity for a formal competition. The unusual lease-to-own deal would have cost the Defense Department approximately $37 billion, according to one government estimate.

But the tanker lease contract never...