What best describes interdependence among countries?

Interdependence among countries refers to a relationship where nations rely on each other for various resources, such as goods, services, and even political and economic stability. This mutual reliance shapes the global economy and promotes international cooperation. When countries engage in trade and exchange resources that they lack, they strengthen their economic ties and create a network of mutual benefits. Such interdependence can be seen in various forms, including the global supply chain, where different countries specialize in producing particular goods and rely on others to supply materials or finished products.

The other options, while related to aspects of international relations, do not capture the essence of interdependence. Complete independence in trade implies no reliance on any other country, which contradicts the concept of interdependence. Political alliances for military purposes reflect a different type of relationship, often focused on security rather than economic cooperation. Unilateral trade agreements suggest one-sided agreements that do not foster mutual reliance or cooperation, which is central to the idea of interdependence.