Gilbert Kaplan says that if Chinese censorship forces out US content companies like Google, the US should retaliate by erecting trade barriers to Chinese computer hardware exports. Nate Anderson at Ars Technica reports:

Dealing with censorship as a trade violation isn’t a new idea. Computer industry lobbying group CCIA was talking up trade complaints as a way to handle Chinese censorship back in January. CEO Ed Black said at the time, “It is increasingly apparent that censorship is a barrier to trade, and that China cannot limit the free flow of information and still comply with its international trade obligations. The Chinese government has said it is gathering more information before deciding how to proceed and we would urge that they look at the issue holistically with government, economic and trade officials involved in the decision.”

Of course, lobbyists aren’t the best source to describe trade law. I’d prefer to consult the folks at IELP, for example.

Banning the consumption of tradable goods and services isn’t a WTO violation per se; international trade law emphasizes non-discrimination in the treatment of foreign and domestic products. Consider Antigua’s online gambling case against the US at the WTO. The basis for its claims was not that the US was obliged to allow online gambling, but that if it allowed domestic online gambling (such as allowed by the Interstate Horseracing Act), it was obliged by its GATS commitments to also allow online gambling provided by foreign suppliers. Similarly, I suspect that censorship only constitutes a trade barrier if foreign sources of information are censored more heavily than domestic providers, i.e. a difference in national treatment.

If China censors both domestic and foreign internet sites, then it is unlikely that its WTO commitments oblige it to liberalize both. Thus, the line of thinking from folks like Dan Drezner and Simon Lester (1, 2) is that WTO law isn’t much of a tool to wield against Chinese censorship.