There are important differences between customs unions and free trade areas. Both types of trading blocs have internal agreements that the parties conclude in order to liberalize and facilitate trade between them. The crucial difference between customs unions and free trade areas lies in their relations with third parties. While a customs union requires all parties to establish and maintain identical external tariffs for trade with non-contracting parties, parties to a free trade area are not subject to such a requirement. Instead, they may introduce and maintain any customs procedure applicable to imports from non-Contracting Parties if they deem it necessary.  In a free trade area without harmonised external tariffs, the Parties will introduce a system of preferential rules of origin to eliminate the risk of trade travel.  In the General Agreement on Tariffs and Trade (GATT 1994), free trade agreements were originally defined as covering only trade in goods.  An agreement with a similar objective, namely to promote the liberalization of trade in services, is referred to in Article V of the General Agreement on Trade in Services (GATS) as an “economic integration agreement”.  In practice, however, the term is now often used [by whom?] to refer to agreements that concern not only goods, but also services and even investment.
Environmental regulations have also become increasingly common in international investment agreements such as free trade agreements. :104 A reliable prediction is that international trade agreements will continue to be controversial. One of the difficulties of the WTO system in recent years has been the problem of maintaining and expanding the liberal world trading system. Multilateral negotiations on trade liberalization are progressing very slowly and the need for consensus among the many WTO members limits the scope of trade reform agreements. As Mike Moore, a new Director-General of the WTO, said, the organization is like a car with an accelerator and 140 handbrakes. While multilateral efforts have reduced tariffs on industrial products, they have had much less success in liberalizing trade in agriculture, textiles and clothing, as well as in other areas of international trade. Recent negotiations, such as the Doha Development Round, have encountered problems and their ultimate success is uncertain. The United States currently has a number of free trade agreements in place. These include multinational agreements such as the North American Free Trade Agreement (NAFTA), which covers the United States, Canada and Mexico, and the Central American Free Trade Agreement (CAFTA), which covers most Central American countries. Despite the possible tensions between the two approaches, multilateral and bilateral/regional trade agreements appear to continue to be part of the global economy. However, the WTO and agreements such as NAFTA have become controversial among groups such as anti-globalization protesters, arguing that such agreements serve the interests of multinationals rather than those of workers, even though trade liberalization is a proven method to improve economic performance and increase overall revenues.
To address this opposition, pressure has been exerted to include labour and environmental standards in these trade agreements. Labour standards contain provisions on minimum wages and working conditions, while environmental standards would prevent trade if there were fears of environmental damage. All these agreements together still do not lead to free trade in its laissez-faire form. U.S. interest groups have successfully lobbied to impose trade restrictions on hundreds of imports, including steel, sugar, automobiles, milk, tuna, beef and denim. First, the customs duties and other rules maintained in each of the signatory parties to a free trade area and applicable to trade with non-parties to such a free trade area at the time of the formation of that free trade area must not be higher or more restrictive than the corresponding duties and other rules that existed in the same signatory parties before the establishment of the free trade area. In other words, the creation of a free trade area to grant preferential treatment among its members is legitimate under WTO law, but parties to a free trade area are not allowed to treat non-contracting parties less favourably than before the creation of the area. A second requirement of Article XXIV is that tariffs and other barriers to trade within the free trade area must be substantially removed.  In the modern world, free trade policy is often implemented by mutual and formal agreement between the nations concerned.
However, a free trade policy may simply be the absence of trade restrictions. The creation of free trade areas is considered an exception to the most-favoured-nation (MFN) principle of the World Trade Organization (WTO), as preferences granted exclusively to each other by parties to a free trade area go beyond their membership obligations.  Although Article XXIV of the GATT allows WTO members to establish free trade areas or to conclude the interim agreements necessary for their establishment, there are several conditions relating to free trade areas or interim agreements leading to the formation of free trade areas. A free trade agreement (FTA) is an agreement between two or more countries in which, among other things, countries agree on certain obligations that affect trade in goods and services, as well as the protection of investors and intellectual property rights. For the United States, the primary purpose of trade agreements is to remove barriers to U.S. exports and protect the United States. Competing interests abroad and improving the rule of law in FTA partner countries. Taken together, these agreements mean that about half of all goods entering the U.S. are duty-free, according to the government.
The average import duty on industrial goods is 2%. However, these advantages must be offset by a disadvantage: by excluding certain countries, these agreements can shift the composition of trade from low-wage countries that are not parties to the agreement to high-cost countries that are. .