An international incident (or diplomatic incident) is a seemingly relatively small or limited action, incident or clash that results in a wider dispute between two or more nation-states. International incidents can arise from unanticipated actions involving citizens, government officials, or armed units of one or more nation-states, or out of a deliberate but small provocative action by espionage agents of one nation-state, or by terrorists, against another nation-state.
An international incident usually arises during a time of relative peace between nation-states, and in general is, on the surface, an unexpected event. Conflicts that grow out of a series of escalating skirmishes between nation-states generally are not considered international incidents; however, terrorist actions can and often do become international incidents. However, historical views of past international incidents often reveal the incident was the flashpoint of a simmering conflict between nation-states, or organizations opposing nation-states.
Wars have often been provoked by international incidents, and diplomatic efforts to prevent international incidents from growing into full-scale armed conflicts often have been unsuccessful. In the aftermath of the First World War, the League of Nations was established to help nations who were parties to an international incident achieve a solution to the incident through diplomatic means. Initially, the League of Nations had some success in working to find diplomatic solutions, however the failure of the League of Nations to prevent World War II resulted in the disbandment of the League of Nations in favor of the United Nations. As with its predecessor, the United Nations provides a means by which nations involved in an international incident can work to resolve the matter diplomatically rather than through the use of force.
The term is also applied to various incidents that can disrupt international commerce, and to celebrities or other well-known people who commit gaffes or otherwise act inappropriately, causing the press and sometimes governments to criticize their actions.
The International Court of Justice keeps a list of legal disputes between nation-states, many of which result from international incidents. The Royal Mail of the United Kingdom keeps a list on its website of current international incidents that might disrupt mail service.  The incidents listed may or may not conform to the definitions given above.