Protectionism can also escalate as other countries retaliate by raising their own trade barriers. That's exactly what happened in the 1920s and 30s with disastrous effects. Even the sectors demanding protection ended up losing. Governments need to be armed against pressure from narrow interest groups, and the WTO system can help. The GATT-WTO system covers a wide range of sectors.
Governments do just that, regularly.
World Trade Organization, rue de Lausanne 154, CH-1211 Geneva 21, Switzerland World Trade Organization 1999.