Most nations encourage free trade by inviting firms to invest and to conduct business there, while encouraging domestic firms to engage in overseas business. These nations do not usually try to strictly regulate imports or discriminate against foreign-based firms. There are, however, some governments that openly oppose free trade. For example, many Communist nations desire self-sufficiency. Therefore, they restrict trade with non-Communist nations. But these restrictions vary with East-West relations.
The most common form of restriction of trade is the tariff, a tax placed on imported goods. Protective tariffs are established in order to protect domestic manufacturers against competitors by raising the prices of imported goods. Not surprisingly, US companies with a strong business tradition in a foreign country may support tariffs to discourage entry by other US competitors.