Are Free-Trade Agreements Actually Protectionist?

Are free-trade agreements protectionist? It sounds like a silly question, but it's always worth asking of regional (as opposed to global) trade pacts -- like the ones the U.S. is seriously considering with the European Union and the Pacific Rim.

Economists are often mocked for free-trade worship, but they're skeptical when appropriate. Jacob Viner, a University of Chicago economist, argued in 1950 that free-trade agreements don't necessarily promote free trade.