Bill Greenwalt is sort of the Pied Piper of military acquisition policy. Where he leads, others often follow. After he wrote a series of op-eds for Breaking Defense recommending major changes to the Pentagon’s acquisition system, Sen. John McCain lured Bill back to his old job at the Senate Armed Services Committee. Greenwalt rewrote the laws, shaking up Defense Department acquisition. Bill is back, pointing to new acquisition problems, this latest one with his former employer — the Government Accountability Office. It’s a doozy, as you’ll see.