Which of the following is a characteristic of alliances?

Alliances are defined by a higher level of control over decisions among member states compared to other types of partnerships, such as coalitions. In alliances, countries often share long-term interests and goals, which fosters a deeper commitment to collaboration. This established framework allows for coordinated strategies and shared resources, enabling member states to act with a unified voice on specific issues and engage in collective security arrangements.

This distinctive characteristic of decision-making is rooted in the formal agreements that define alliances, often accompanied by treaties or ongoing diplomatic relations. Such arrangements are designed for stability and mutual benefit, which reflects the commitment of member nations to work closely together on political, military, and economic matters.

In contrast, the other characteristics outlined in the choices signify different aspects of alliances or other collaborative forms: they can be more informal or short-lived, and military strength is just one element of the cooperation that exists within an alliance, not the sole basis for it.