PSEB SS Defence Studies key terms

The academic study of how states organise armed forces, plan strategy, and manage security, drawing on history, politics, geography and technology rather than training soldiers for combat.

The condition in which a state protects its people, territory, economy and institutions from external attack and internal disruption, using military, diplomatic, economic and intelligence means together.

The core goals a state pursues abroad and at home, such as territorial integrity, economic growth and regional stability, which guide how defence resources are allocated and used.

The art of matching ends, ways and means: deciding what political objectives matter, choosing how to reach them, and committing only the resources actually available to support that plan.

A state's broad, long-term plan that combines military power with diplomacy, trade, alliances and domestic policy to secure its survival and interests over decades rather than single campaigns.

The short-term techniques used by units on the battlefield to win engagements, such as fire and movement, ambush layouts and flanking, which serve objectives set at the strategic level.

An officially approved set of principles telling a military how it intends to fight, covering organisation, equipment priorities and command style, so that separate units act in a coordinated way.

Preventing an adversary from acting by convincing its leaders that the expected costs and risks of aggression will clearly outweigh any gains they hope to obtain.

The Cold War logic that a full nuclear exchange would destroy both attacker and defender, so neither side dares launch first; it depends on survivable second-strike forces.

The ability of a country's nuclear forces to survive a first attack and still retaliate, usually achieved through submarines, hardened silos and mobile launchers rather than vulnerable aircraft alone.

A nuclear arsenal delivered by three separate systems - land-based missiles, submarine-launched missiles and bomber aircraft - so that no single enemy strike can disarm the country.

A declared policy that a nuclear-armed state will not be the first to use nuclear weapons, reserving them only for retaliation, which is meant to reduce escalation risks.

A formal agreement between states to consult and assist each other militarily, often pledging mutual defence, sharing intelligence and conducting joint exercises to strengthen collective security.

A system in which member states agree that aggression against any one of them is treated as aggression against all, and they act together to stop it, as the UN Charter envisages.

Operations in which UN-authorised troops, usually lightly armed and impartial, monitor ceasefires and protect civilians in conflict zones with the consent of the main parties.

Military action authorised to impose peace when consent is absent or has collapsed, permitting force beyond self-defence, unlike traditional peacekeeping which relies on consent.

Written instructions telling troops when and how much force they may use, covering warnings, self-defence and civilian protection, so that action stays within legal and political limits.

The arrangement of authority and information systems through which commanders direct forces, receive reports and adjust plans, ensuring that decisions reach units quickly and reliably.

The planning and movement of supplies, fuel, ammunition, spares and medical support that keeps forces operating, often deciding whether a campaign can be sustained at all.

The process of calling up reserves, activating units and converting industry to military output so that a peacetime force becomes ready for war within a planned period.

Part-time personnel who train periodically and can be called to full-time duty in an emergency, giving a country depth beyond its smaller standing army.

A volunteer reserve component raised regionally for local defence and support tasks, allowing citizens to serve part-time while continuing civilian employment.

A strategy of wearing down an opponent's manpower, equipment and will through sustained pressure rather than a single decisive blow, usually demanding superior resources.

Conflict between opponents of very unequal strength, where the weaker side avoids head-on battle and uses guerrilla raids, ambushes or terrorism to exploit the stronger side's vulnerabilities.

An organised armed movement that seeks to overthrow or weaken an established authority through guerrilla tactics, political mobilisation and control of population, not conventional battle lines.

The mix of military, political and economic measures used to defeat an insurgency, stressing population protection, intelligence and legitimate local governance over indiscriminate firepower.

The combined use of regular troops, irregular fighters, cyber attacks, disinformation and economic pressure below the threshold of open war, making attribution and response difficult.

Attacks through computer networks to disrupt military systems, infrastructure or information, conducted in peacetime or war and often hard to trace to a specific state.

The power grids, water systems, transport networks, communications and financial systems whose failure would seriously damage a country, making them priority targets for protection.

The deliberate use or threat of violence against civilians or non-combatants to create fear and force political change, condemned under international law regardless of stated cause.

The study of how geography - location, borders, resources, sea lanes and chokepoints - shapes the power and security choices of states and their rivalries.

A position that gives military or economic advantage, such as a strait, mountain pass or border region, because whoever controls it can influence movement and trade.

A narrow passage on a sea route, like a strait or canal, through which much trade must pass, so blocking it can disrupt an economy and invite military confrontation.

A state's capacity to use the oceans for trade, transport and naval operations, and to deny that use to rivals, resting on fleets, ports and merchant shipping.

The use of aircraft and missiles for reconnaissance, strike, transport and air defence, giving speed and reach but requiring bases, fuel and skilled maintenance.

Negotiated limits on weapons - numbers, types or testing - intended to reduce the risk of war, curb costly arms races and build confidence between rival states.

The reduction or elimination of armed forces and weapons, often pursued through treaties, aiming beyond limits to remove whole categories of arms from national arsenals.

Efforts to stop the spread of nuclear weapons to new states while encouraging existing powers to reduce arsenals, monitored through safeguards and international inspections.