The United Nations was founded in 1945 to replace the ineffective League of Nations. Its primary mandate is to maintain international peace and security through the principle of collective security, where member states agree to act together to deter aggression and respond to threats against any individual state.

The 1990-91 Gulf War was a landmark application of the principle of collective security. Following Iraq's invasion and annexation of Kuwait, the United Nations Security Council authorized a multinational coalition to expel Iraqi forces and restore the sovereignty of Kuwait, demonstrating the international community's commitment to upholding territorial integrity against unprovoked aggression.

The United Nations Charter established the principle of collective security as a primary mechanism for maintaining international peace and security. Under Chapter VII, the UN Security Council is empowered to take collective action, including diplomatic, economic, or military measures, to address threats to peace, breaches of the peace, or acts of aggression. This system was designed to prevent the recurrence of global conflicts by ensuring that the international community acts in unison against aggressors.

Institutionalized cooperation involves the creation of formal international organizations and regimes to facilitate communication, reduce transaction costs, and provide a platform for conflict resolution. By establishing norms and rules, these institutions help states manage their security concerns collectively rather than relying solely on unilateral military buildup, thereby mitigating the risks associated with the anarchic international system.

Collective security systems face significant hurdles in practice. Identifying the true aggressor is often difficult due to propaganda and complex conflict origins. Furthermore, the idealistic assumption that all aggression is equally unacceptable ignores geopolitical realities. Finally, pre-existing alliances, historical grievances, and deep-seated friendships often prevent states from acting impartially, as they may prioritize their own national interests over the collective enforcement of international peace.

Collective security is a security arrangement in which all states in a system agree that a breach of peace by any one state is a concern for all. It functions on the principle that an attack on one member is treated as an attack on the entire community, necessitating a unified response to deter or punish the aggressor. This system aims to replace the competitive balance of power with a cooperative framework for maintaining global stability.

Collective security relies on the principle that an attack on one member is an attack on all. For this to work, there must be a clear, shared definition of what constitutes an act of aggression. Without a consensus on what triggers the collective response, the regime cannot effectively mobilize its members to deter or punish the aggressor.

The period of 1990-1991, specifically surrounding the Gulf War, is frequently cited as a rare instance where the UN Security Council successfully authorized collective security measures. The international coalition formed to reverse Iraq's invasion of Kuwait demonstrated a unified response to aggression, which many scholars view as a functional application of the collective security principle.

Collective security is a system where states agree to act together to deter aggression, viewing an attack on one as an attack on all. It relies on established norms and procedures to manage power and maintain peace. While the provided answer is 'Collective Security', this definition also closely mirrors the concept of an 'International Regime', which is a broader term for sets of rules and norms.

The 1990-1991 Gulf War is frequently cited as a rare instance where the United Nations Security Council successfully authorized a collective military response to reverse an act of aggression, specifically Iraq's invasion of Kuwait. This operation, sanctioned under Chapter VII of the UN Charter, demonstrated the potential for member states to unite against a common aggressor to restore international peace and security, contrasting with failures in other regional conflicts.