As the successor to the GATT, the WTO aims to liberalise trade on a global scale. But the WTO's SPS and TBT regimes pose delicate problems of balance when it comes to establishing and implementing trade rules. The fact is that the trade restrictions provided for in certain agreements run the risk of being used for expedient protection purposes. Indeed, the need to combat global warming and protect public health means that governments are resorting to restrictive measures based on the precautionary principle. To what extent does this practice not contradict the objective of the organisation? The answers to this question will be of interest to students and specialists in international trade issues, as well as to the organisation's officials.