I. Lines of Actions: The maintenance of international peace and security is a very important purpose of the United Nations.United Nations has pursed broadly three lines of action.They are:

1. The efforts of diplomatic and peaceful character.

2. The use of sanctions and military powers and 

3. The development of military personnel for restoration of peace without the due of force.

II. Peaceful Solution:

1. The United Nations has found peaceful solutions in nearly 172 disputes and conflicts during the last 50 years. It has encouraged and negotiated settlement by mediating between the countries.

2. In 1962 the Secretary General U Thant's mediation helped to avoid direct military confrontation between the United States and the Soviet Union in Cuba.

3. The United Nations investigated in the 1980s the accusation about the use of banned chemical weapons against civilian population in the Iraq-Iran war.

4. The second aspect of the United Nations role relates to enforcement action aimed at reversing threats to peace and aggressions. The Security Council imposed economic and diplomatic sanctions against the ten countries so far.

5. The third aspect of the United Nations role in the maintenance of world peace refers to the technique of peace-keeping. Peacekeeping means deployment of military and civilian officials for separating the working parties.

6. Some of the relevant examples refer to Cambodia, Georgia, Mozambique, Somalia, etc