In which context are tariffs primarily used?

Tariffs are primarily used as a means of regulating trade between countries. They are taxes imposed on imported goods, designed to increase the cost of foreign products in the domestic market. This can encourage consumers to buy domestic products instead, thereby supporting local industries and protecting them from foreign competition.

By adjusting tariff rates, governments can influence trade balances, protect nascent industries, and generate revenue. Tariffs can also serve as a tool for negotiating trade agreements, where changes in tariffs might be used as leverage in discussions with other nations. This regulatory function is fundamental to international trade policy and plays a critical role in shaping economic relationships between countries.

In contrast, the other contexts provided do not accurately capture the primary role of tariffs. Building international alliances often involves diplomatic negotiations and collaborative efforts, rather than imposing tariffs. Military strategies involve defense and security measures, which do not relate to tariffs' economic function. Lastly, while tariffs may have indirect effects on humanitarian efforts, such as by influencing the price of imported goods that could aid in humanitarian aid, they are not directly used for promoting such initiatives.