conflict

A conflict is either physical or psychological. It is when two people or more (at least two groups of people) come into collision or disagreement, fights, struggles or quarrels. The protagonist and the antagonist in movies and books are always in a state of conflict.

An example of a conflict is the war between Iraq and the U.S.

Source: http://www.toastmasters.org/Members/OfficerResources/eLearning/DistrictOfficerModules/LeadingTeams/ResolvingConflict.aspx