“For want of a nail the shoe was lost; for want of a shoe the horse was lost; for want of a horse the battle was lost; for the failure of battle the kingdom was lost—All for the want of a horse-shoe nail.”

That proverb reflects what could be the fate of the Trans-Pacific Partnership, the multilateral trade agreement the United States and 11 other Pacific Rim countries recently signed after seven years of negotiation.

What all of the countries have in common is a commitment to overcome domestic political obstacles to expanding free trade.

Unfortunately, what U.S. negotiators appear to have agreed to in October is a final draft that might not pass Congress.

An important part of the deal is protection of intellectual property—including copyright, trademarks and patents—which are necessary for commercial and scientific innovation. The biggest obstacle to congressional approval, however, appears to be the deal’s inadequate protection of intellectual property in “biologic” medicines.