The single-source test

A defense merger now answers to a supply-chain question, not a price question. Call it the single-source test: the surviving firm is judged by whether it becomes the only outfit that can keep a weapons system flying, and the deal is dead on arrival if the answer is yes.

The mechanism is simple to apply, hard to game, and almost impossible to argue with in public. Step one: name the platform the suppliers serve. Step two: count the qualified vendors for the parts that keep it running. Step three: ask whether the deal reduces that count to one. If yes, the warfighter cannot afford a single point of failure — and the antitrust complaint writes itself.

TransDigm's abandoned bid for Stellant Systems is the seed. Both firms built radar and electronic components for the Navy's Aegis Combat System and the Air Force's F-16; as Under Secretary Duffey said, the combination would have left one supplier where two had competed. DOJ told the parties it would sue in federal court to block the transaction, and TransDigm walked before the complaint landed.

The reader's filter is now live: every defense roll-up from here is single-source guilty until proven diversified. The honest counter is that "single-source risk" is standard antitrust language for any horizontal defense tie-up, and the test collapses the day DOJ clears a deal that produces one. Watch the next announcement. If it passes, this was a story; if it doesn't, this is a doctrine.