In short, there are at least three ominous implications of revoking PNTR.  First, the United States would be reversing a bedrock principle of the global trading system—to avoid discrimination.  While regular readers certainly know that the system has been under tremendous pressure, it has continued to function as a brake on all kinds of otherwise possible unilateral actions by all World Trade Organization (WTO) members.  This brake will be gone if the US explicitly opts for discrimination. Second, while some supporters of revoking PNTR seem to suggest that this action will be limited to China, once the brake is gone, it is gone for all.  There is little reason to think that others will not opt to do something similar, including against the United States.  Hence, businesses should be extremely concerned that their “foreign” products and services in markets around the world will suddenly be targets for all sorts of actions, starting with unilateral adjustments in tariff levels and moving towards outright discrimination in treatment over foreign products in markets.  Some could argue that firms already face a range of discriminatory actions in different markets, particularly with inconsistent application of non-tariff measures, unequal licensing requirements, or generally unfair trade treatment.  However, these measures are actually quite restrained compared to what will happen in the total absence of MFN. Third, as always, the worst damage is likely to be felt by firms and communities that are already at the margins.  Poor developing countries and small firms are going to be badly hit by adjustments to the global trading rules.  Without a strong network of trade agreements in place to help cushion the blows, sudden adjustments in tariff rates, differentiated customs treatment, denied access to services markets, rejections of licenses or qualifications, and restrictions on movement of business people will make trade increasingly difficult or even impossible across borders.