17 even liberation of a defined area. Employment of military force may not be able to stamp out an insurgency but may help to contain it. In most cases, it is a combination of military force backed by appropriate political and economic measures which can adequately resolve such situations. The latter part acquires even more importance than the use of force. 2.10 Irregular War. Irregular war may take many forms of which terrorism and guerrilla war are two important ones. Terrorism is the unlawful use or threatened use of force or violence against people or property to terrorise, coerce or intimidate governments or societies; this is most often resorted to with the aim of achieving political, religious, or ideological objectives. Terrorism thrives on a fear psychosis and could be achieved by arson, sabotage, hijacking, hoaxes, maiming, bombing, seizure, kidnapping, assassination, taking hostages, raids, ambushes and the threat to use or use of WMD. Guerrilla war is an irregular form of warfare which includes acts of subversion, assassination, attack on supply lines and terrorism. Terrorism and guerrilla warfare can be employed across the entire spectrum of conflict. Non-Combat Operations and Aid to Civil Authorities 2.11 Non-combat operations are defined as military operations where the use of force may not be necessary but, at times, the most minimal use of force, or threat to use force, may be required. Non-combat operations include aid to civil authorities, disaster relief, humanitarian assistance and peacekeeping operations. NUCLEAR CHEMICAL AND BIOLOGICAL WARFARE 2.12 Nuclear Warfare. A conventional war may escalate to a nuclear war when any of the belligerents decide to use nuclear weapons through any means of delivery to avoid defeat in the sphere of conventional warfare or to safeguard its vital national interests or even with the aim to bring the war to a decisive end. World opinion is against the use of such weapons. India is a nuclear weapon state and pursues a policy