War

Part of the Stele of the Vultures depicting heavy infantry marching in formation

Part of the Bayeux Tapestry depicting Norman heavy cavalry charging Saxon shield wall

Painting of Napoleon and his troops in winter retreating from Moscow

Soldiers wading ashore from landing craft on D-Day

British rhomboid tank and soldiers preparing to advance

Clockwise from top-left:
Ancient warfare: Stele of the Vultures, c. 2500 BCE
Medieval warfare: Battle of Hastings, 1066
Early modern warfare: Retreat from Moscow, 1812
Industrial age warfare: Battle of the Somme, 1916
Modern warfare: Normandy landings, 1944
Nuclear warfare: Atomic bombing of Nagasaki, 1945

War
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Outline Index
History Prehistoric Ancient Post-classical Early modern Industrial Modern
Military Organization Command and control Defense ministry Reserves Ranks Branches: Army Navy Air force Marines Coast guard Border guard Special forces Cyber force Space force Specialties: Staff Engineers Intel Recon Medical Police Diving Pilot Land units: Infantry Armor Cavalry Artillery Special forces Signal corps Naval units: Warships Submarines Aircraft carriers Landing craft Auxiliary ships Air units: Fighters Bombers Command Close air support Electronic-warfare Reconnaissance Combat systems: Fire-control system Fire-control radar Director (military) Combat information center Sonar Radar Historical: Ship gun fire-control Gun data computer Torpedo data computer Development: Basic training Military maneuvers Combat training
Battlespace Aerospace Aerial Airborne Space Land Cold-region Desert Fortification Jungle Mountain Urban Subterranean Tunnel Sea Amphibious Blue Brown Green Surface Underwater Seabed Cyber Information Night
Technology Air defense Armor Artillery Barrage Biological Camouflage Cavalry Horses Air cavalry Chemical Combined arms Conventional Cyber Denial Disinformation Drone / Robot Electromagnetic Firearms Infantry Loitering Missile Music Nuclear Psychological Radiological Submarine Unconventional
Tactics List of military tactics Aerial Airlift Air assault Airbridge Airdrop Anti-aircraft Anti-sub Anti-tank Battle Cavalry Charge CQC Counterattack Counterinsurgency Convoy Defeat in detail Foxhole Drone Envelopment Formation Guerrilla Naval Shock Rapid dominance Encirclement Investment Siege Swarm Screen Tactical objective Target saturation Trench Withdrawal
Operational Military operation Special Operations research Blitzkrieg Expeditionary Deep operation Maneuver Operational maneuver group Raid Covert Stay-behind
Strategy List of military strategies and concepts Military campaign Anti-access Attrition Commerce raiding Counter-offensive Culminating Defense in depth Fabian Empty fort Kinetic Mosaic Deception Defensive Depth Goal Nuclear Naval Offensive Scorched earth
Grand strategy Asymmetric Blockade Broken-backed Class Cold war Colonial Conquest Containment Divide and conquer Economic Endemic Fleet in being Irregular Liberation Limited Network-centric New generation Perpetual Political Princely Proxy Religious Resource Strategic Succession Technology Theater Total war World war
Administrative Branch Policy Staff Training Service Sociology
Organization Area of responsibility Chain of command Command and control Doctrine Order of battle Principles of war Economy of force Medicine Engineers Intelligence Ranks
Personnel Recruitment Conscription Draft evasion Mobilization Training Specialism Soldier Morale Volunteer Women Children Transgender Harassment Conscientious objector Conscription and sexism Counter-recruitment
Logistics History War economy Arms industry Materiel Train Supply-chain management Defense industrial base Base MOB FOB Outpost
Science Power projection Loss-of-strength gradient Lanchester's laws Force multiplication Morale
Law Belligerent Occupation Armistice Ceasefire Court-martial Desertion Geneva Conventions Geneva Protocol Islamic rules Justice Lawful / Unlawful combatant Perfidy Regular / Irregular Jewish laws on war Right of conquest Right of self-defense Rules of engagement Self-determination Martial law War crime War and genocide War treason Warlord
Theory Air supremacy Appeasement Command of the sea Deterrence theory Full-spectrum dominance Overmatch Just war theory Principles of war Philosophy of war Security dilemma Tripwire force Wargaming Simulation Exercises Combat effectiveness Center of gravity
Non-warfare Arms control Counter-insurgency Deterrence Disaster response Gray-zone Gunboat diplomacy Humanitarian aid Law enforcement Low-intensity conflict Military engineering Peacekeeping Peacebuilding Peace through strength Show of force
Culture Awards and decorations Battle cry Warrior War film Military science fiction War novel Anti-war movement Foot drill War song Psychology Uniform Wargame Militarization / Militarism Antimilitarism Camp follower
Related Women in war War resister War studies Horses in warfare Wartime sexual violence Fifth column Mercenary Pacifism Privateer Private military company Soldiers are murderers
Category

War is an armed conflict between the armed forces of states, or between governmental forces and armed groups that are organized under a certain command structure and have the capacity to sustain military operations, or between such organized groups.

It is generally characterized by widespread violence, destruction, and mortality, using regular or irregular military forces. War aims typically involve the pursuit of political, economic, or territorial objectives. Warfare refers to the common activities and characteristics of types of war, or of wars in general. Total war is warfare that is not restricted to purely legitimate military targets, and can result in massive civilian or other non-combatant suffering and casualties.

War has changed in numerous ways over the course of history. Since 1945, great power wars, territorial conquests and war declarations have declined in frequency. However, war in general has not necessarily declined. Civil wars have increased in absolute terms since 1945. Wars have been increasingly regulated by international humanitarian law. Battle deaths and casualties have declined, in part due to advances in military medicine.