Terrorism and war.

Terrorism is "the systematic use of terror especially as a means of coercion."[2] There is no internationally agreed legal definition.[3][4] In one modern definition of terrorism, it is violence against civilians to achieve political or ideological objectives by creating fear.[5] Most common definitions of terrorism include only those acts which are intended to create fear (terror), are perpetrated for an ideological goal (as opposed to a lone attack), and deliberately target or disregard the safety of non-combatants. Some definitions also include acts of unlawful violence and war.

Terrorism is also a form of unconventional warfare and psychological warfare. The word is politically and emotionally charged,[6] and this greatly compounds the difficulty of providing a precise definition. One 1988 study by the US Army found that over 100 definitions of the word "terrorism" have been used.[7]. A person who practices terrorism is a terrorist.

Terrorism has been used by a broad array of political organizations in furthering their objectives; both right-wing and left-wing political parties, nationalistic, and religious groups, revolutionaries and ruling governments.[8] The presence of non-state actors in widespread armed conflict has created controversy regarding the application of the laws of war.

An International Round Table on Constructing Peace, Deconstructing Terror (2004) hosted by Strategic Foresight Group recommended that a distinction should be made between terrorism and acts of terror. While acts of terrorism are criminal acts as per the United Nations Security Council Resolution 1373 and domestic jurisprudence of almost all countries in the world, terrorism refers to a phenomenon including the actual acts, the perpetrators of acts of terrorism themselves and their motives. There is disagreement on definitions of terrorism. However, there is an intellectual consensus globally, that acts of terrorism should not be accepted under any circumstances. This is reflected in all important conventions including the United Nations counter terrorism strategy, the decisions of the Madrid Conference on terrorism, the Strategic Foresight Group and ALDE Round Tables at the European Parliament.

War is any large scale, violent conflict. The conduct of war extends along a continuum, from the almost universal tribal warfare that began well before recorded human history, to wars between city states, nations, or empires. By extension, the word is now used for any struggle, as in the war on drugs or the war on terror. It was once thought humans were the only creatures who fought wars, but closer observation of animal life has discovered wars between ant colonies and chimpanzee tribes.

A group of combatants and their support is called an army on land, a navy at sea, and air force in the air. Wars may be prosecuted simultaneously in one or more different theatres. Within each theatre, there may be one or more consecutive military campaigns. A military campaign includes not only fighting but also intelligence, troop movements, supplies, propaganda, and other components. Continuous conflict is traditionally called a battle, although this terminology is not always fed to conflicts involving aircraft, missiles or bombs alone, in the absence of ground troops or naval forces. A civil war is the use of force to resolve internal differences
Conventional warfare is an attempt to reduce an opponent's military capability. It is a war between nation-states and nuclear or biological weapons are not usually used.
Unconventional warfare is an attempt to achieve military victory through acquiescence, capitulation, or clandestine support for one side of an existing conflict.
Nuclear warfare is a war in which nuclear weapons are used.

Civil war is a war where the forces in conflict belong to the same country or empire or other political entity.
Asymmetric warfare, is a conflict between two populations of drastically different levels of military mechanisation. This type of war often results in guerrilla tactics. Military action produces a very small percentage of air pollution emissions. Intentional air pollution in combat is one of a collection of techniques collectively called chemical warfare. Poison gas as a chemical weapons was principally used during World War I, and resulted in an estimated 91,198 deaths and 1,205,655 injuries.[citation needed] Various treaties have sought to ban its further use. Non-lethal chemical weapons, such as tear gas and pepper spray, are widely used, sometimes with deadly effect