A counter-insurgency or counterinsurgency (COIN) can be defined as "comprehensive civilian and military efforts taken to simultaneously defeat and contain insurgency and address its root causes". An insurgency is a rebellion against a constituted authority when those taking part in the rebellion are not recognized as belligerents. It is
the organized use of subversion and violence to seize, nullify or challenge political control of a region. As such, it is primarily a political struggle, in which both sides use armed force to create space for their political, economic and influence activities to be effective.
Counter-insurgency campaigns of duly-elected or politically recognized governments take place during war, occupation by a foreign military or police force, and when internal conflicts that involve subversion and armed rebellion occur. The most effective counterinsurgency campaigns
integrate and synchronize political, security, economic, andinformational components that reinforce governmental legitimacy and effectiveness while reducing insurgent influence over the population. COIN strategies should be designed to simultaneously protect the population from insurgent violence; strengthen the legitimacy and capacity of government institutions to govern responsibly and marginalize insurgents politically, socially, and economically.
Counter-insurgency is normally conducted as a combination of conventional military operations and other means, such as demoralization in the form of propaganda, psy-ops, and assassinations. Counter-insurgency operations include many different facets: military, paramilitary, political, economic, psychological, and civic actions taken to defeat insurgency.
To understand counter-insurgency, one must understand insurgency to comprehend the dynamics of revolutionary warfare. Insurgents capitalize on societal problems, often called gaps; counter-insurgency addresses closing the gaps. When the gaps are wide, they create a sea of discontent, creating the environment in which the insurgent can operate.