FROM the United Nations High Commissioner on Human Rights, we get the following synthesis of legal documents on the nature of terrorism and its legal definition:

Terrorism is commonly understood to refer to acts of violence that target civilians in the pursuit of political or ideological aims. In legal terms, although the international community has yet to adopt a comprehensive definition of terrorism, existing declarations, resolutions and universal “sectoral” treaties relating to specific aspects of it define certain acts and core elements. In 1994, the General Assembly’s Declaration on Measures to Eliminate International Terrorism, set out in its Resolution 49/60, stated that terrorism includes “criminal acts intended or calculated to provoke a state of terror in the general public, a group of persons or particular persons for political purposes” and that such acts “are in any circumstances unjustifiable, whatever the considerations of a political, philosophical, ideological, racial, ethnic, religious or other nature that may be invoked to justify them.”