A government does not need to take concrete steps to promote free trade. This upside-down attitude is called “laissez-faire trade” or trade liberalization. There are significant differences between unions and free trade zones. Both types of trading blocs have internal agreements that the parties enter into to liberalize and facilitate trade between them. The key difference between unions and free trade zones is their approach to third parties [lack of ambiguity needed]. While a customs union requires all parties to apply and maintain identical external tariffs on trade with non-parties, parties to a free trade area are not subject to such a requirement. Instead, they can set and maintain any customs regime for imports from non-parties, as they see as necessary.  In a free trade area without harmonized external tariffs, the parties will adopt a system of preferential rules of origin to eliminate the risk of trade diversion [necessary ambiguities].  The notion of free trade is the opposite of trade protectionism or economic isolationism. All these agreements still do not collectively add up to free trade in its form of free trade. Bitter interest groups have successfully imposed trade restrictions on hundreds of imports, including steel, sugar, automobiles, milk, tuna, beef and denim. The General Agreement on Tariffs and Trade (GATT 1994) originally defined free trade agreements that were to include only trade in goods.  An agreement with a similar purpose, namely the improvement of trade in services, is referred to as the “economic integration agreement” in Article V of the General Agreement on Trade in Services (GATS).
 However, in practice, the term is now commonly used [by whom?] to refer to agreements that concern not only goods, but also services and even investments. Environmental provisions have also become increasingly common in international investment agreements, such as free trade agreements. :104 Free trade agreements aim to increase trade between two or more countries. The six main advantages of strengthening international trade are that the failure of Doha has enabled China to reach a global level of trade.