Nationalism shapes foreign relations by promoting the interests and identity of a nation-state, often prioritizing domestic concerns over international cooperation. Nationalist sentiment can influence diplomatic strategies, trade agreements, and military alliances, leading countries to adopt more protectionist or adversarial stances. While nationalism can bolster national unity and pride, it may also create tension with other nations, complicating collaboration on global challenges such as climate change or security threats. Hence, nationalism has both unifying and divisive implications in international relations.