Final answer:
When states manipulate international trade to strengthen domestic industries and inhibit foreign competition, it is called protectionism. This involves implementing trade barriers to shield domestic producers and workers. However, long-term protectionism can have adverse effects like hindering market competition.
Step-by-step explanation:
When states try to manipulate international trade to strengthen one or more domestic industries and shelter them from world markets, it is referred to as protectionism. Protectionism takes various forms, such as imposing trade barriers like tariffs, import quotas, and nontariff barriers. These policies aim to shield domestic producers and workers from foreign competition. However, it is important to note that long-term protectionism can have negative consequences, such as hindering market competition and relying on government subsidies.