A no-fly zone in terms of international relations refers to an airspace where aircraft are prohibited from flying, typically imposed by a governmental authority for security reasons. This measure can be established during conflicts to protect civilians or prevent hostile aircraft from engaging in military actions. A no-fly zone may be enforced by military intervention and is often associated with humanitarian objectives. However, its implementation can be controversial, as it may escalate tensions and lead to broader military conflicts, highlighting the complexities of international diplomacy and security interventions.