Deterrence theory in the context of "Forward presence"

In international relations, coercion refers to the imposition of costs by a state on other states and non-state actors to prevent them from taking an action (deterrence) or to compel them to take an action (compellence). Coercion frequently takes the form of threats or the use of limited military force. It is commonly seen as analytically distinct from persuasion (which may not necessarily involve the imposition of costs), brute force (which may not be intended to shape the adversary's behavior), or full-on war (which involves the use of full military force).

Coercion takes the form of either deterrence or compellence. Compellence has been characterized as harder to successfully implement than deterrence because of difficulties in getting actors to withdraw actions. One influential typology of coercion distinguishes between strategies to punish an adversary, raise the risk for an adversary, or deny the adversary from achieving their objectives. Successful instances of coercive diplomacy in one case may have a deterrent effect on other states, whereas a reputation for a lack of resolve may undermine general deterrence and future compellence.

In general, compliance means conforming to a rule, such as a specification, policy, standard or law. Compliance has traditionally been explained by reference to deterrence theory, according to which punishing a behavior will decrease the violations both by the wrongdoer (specific deterrence) and by others (general deterrence). This view has been supported by economic theory, which has framed punishment in terms of costs and has explained compliance in terms of a cost-benefit equilibrium (Becker 1968). However, psychological research on motivation provides an alternative view: granting rewards (Deci, Koestner and Ryan, 1999) or imposing fines (Gneezy Rustichini 2000) for a certain behavior is a form of extrinsic motivation that weakens intrinsic motivation and ultimately undermines compliance.

Regulatory compliance describes the goal that organizations aspire to achieve in their efforts to ensure that they are aware of and take steps to comply with relevant laws, policies, and regulations. Due to the increasing number of regulations and need for operational transparency, organizations are increasingly adopting the use of consolidated and harmonized sets of compliance controls. This approach is used to ensure that all necessary governance requirements can be met without the unnecessary duplication of effort and activity from resources.

An arms race occurs when two or more groups compete in military superiority. It consists of a competition between two or more states to have superior armed forces, concerning production of weapons, the growth of a military, and the aim of superior military technology. Unlike a sporting race, which constitutes a specific event with winning interpretable as the outcome of a singular project, arms races constitute spiralling systems of on-going and potentially open-ended behavior.

The existing scholarly literature is divided as to whether arms races correlate with war. International-relations scholars explain arms races in terms of the security dilemma, engineering spiral models, states with revisionist aims, and deterrence models.

Collective security is arrangement between states in which the institution accepts that an attack on one state is the concern of all and merits a collective response to threats by all. Collective security was a key principle underpinning the League of Nations and the United Nations. Collective security is more ambitious than systems of alliance security or collective defense in that it seeks to encompass the totality of states within a region or indeed globally.

The premise of a collective security arrangement is that it serves as a deterrent to aggression by committing an international coalition against any aggressor. While collective security is an idea with a long history, its implementation in practice has proved problematic.

An aircraft carrier is a warship that serves as a seagoing airbase, equipped with a full-length flight deck and hangar facilities for supporting, arming, deploying and recovering shipborne aircraft. Typically it is the capital ship of a fleet (known as a carrier battle group), as it allows a naval force to project seaborne air power far from homeland without depending on local airfields for staging aircraft operations. Since their inception in the early 20th century, aircraft carriers have evolved from wooden vessels used to deploy individual tethered reconnaissance balloons, to nuclear-powered supercarriers that carry dozens of fighters, strike aircraft, military helicopters, AEW&Cs and other types of aircraft such as UCAVs. While heavier fixed-wing aircraft such as airlifters, gunships and bombers have been launched from aircraft carriers, these aircraft do not often land on a carrier due to flight deck limitations.

The aircraft carrier, along with its onboard aircraft and defensive ancillary weapons, is the largest weapon system ever created. By their tactical prowess, mobility, autonomy and the variety of operational means, aircraft carriers are often the centerpiece of modern naval warfare, and have significant diplomatic influence in deterrence, command of the sea and air supremacy. Since the Second World War, the aircraft carrier has replaced the battleship in the role of flagship of a fleet, and largely transformed naval battles from gunfire to beyond-visual-range air strikes. In addition to tactical aptitudes, it has great strategic advantages in that, by sailing in international waters, it does not need to interfere with any territorial sovereignty and thus does not risk diplomatic complications or conflict escalation due to trespassing, and obviates the need for land use authorizations from third-party countries, reduces the times and transit logistics of aircraft and therefore significantly increases the time of availability on the combat zone.

A military alliance is a formal agreement between nations that specifies mutual obligations regarding national security. In the event a nation is attacked, members of the alliance are often obligated to come to their defense regardless if attacked directly. Military alliances can be classified into defense pacts, non-aggression pacts, and ententes. Alliances may be covert (as was common from 1870 to 1916) or public.

According to a 2002 dataset of military alliances, there have been 538 alliance treaties from 1815 to 2003. The vast majority of the alliances involve commitments to come to the military support of one ally involved in war. The vast majority are defensive in nature. Since the end of the Second World War, military alliances have usually behaved less aggressively and act more as a deterrent. A 2025 analysis of alliances across the 19th and 20th century found that alliances overall tend to deter war.

Power projection (or force projection or strength projection) in international relations is the capacity of a state to deploy and sustain forces outside its territory. The ability of a state to project its power into an area may serve as an effective diplomatic lever, influencing the decision-making processes and acting as a potential deterrent on other states' behavior.

This ability is a crucial element of a state's power in international relations. Any state able to direct its military forces outside its territory might be said to have some level of power projection capability, but the term itself is used most frequently in reference to militaries with a worldwide reach (or at least significantly broader than a state's immediate area). Even states with sizable hard power assets (such as a large standing army) may only be able to exert limited regional influence so long as they lack the means of effectively projecting their power on a global scale. Generally, only a select few states are able to overcome the logistical difficulties inherent in the deployment and direction of a modern, mechanized military force. Allies and partners can take up or share some of the burden of power projection. One measure of the capability of a state to project power is the loss-of-strength gradient, until a culminating point is apparent to others, once an operation is underway.

The use of toxic chemicals as weapons dates back thousands of years, but the first large-scale use of chemical weapons was during World War I. They were primarily used to demoralize, injure, and kill entrenched defenders, against whom the indiscriminate and generally very slow-moving or static nature of gas clouds would be most effective. The types of weapons employed ranged from disabling chemicals, such as tear gas, to lethal agents like phosgene, chlorine, and mustard gas. These chemical weapons caused medical problems. This chemical warfare was a major component of the first global war and first total war of the 20th century. Gas attack left a strong psychological impact, and estimates go up to about 90,000 fatalities and a total of about 1.3 million casualties. However, this would amount to only 3–3.5% of overall casualties, and gas was unlike most other weapons of the period because it was possible to develop countermeasures, such as gas masks. In the later stages of the war, as the use of gas increased, its overall effectiveness diminished. The widespread use of these agents of chemical warfare, and wartime advances in the composition of high explosives, gave rise to an occasionally expressed view of World War I as "the chemist's war" and also the era where weapons of mass destruction were created.

The use of poison gas by all major belligerents throughout World War I constituted war crimes as its use violated the 1899 Hague Declaration Concerning Asphyxiating Gases and the 1907 Hague Convention on Land Warfare, which prohibited the use of "poison or poisoned weapons" in warfare. Chemical weapons in World War II saw widespread use by Germany during the Holocaust and by Japan against China. Battlefield use against Western Allies was prevented by deterrence.

Nuclear weapons delivery is the technology and systems used to place a nuclear weapon at the position of detonation, on or near its target. All nine nuclear states have developed some form of medium- to long-range delivery system for their nuclear weapons. Alongside improvement of weapons, their development and deployment played a key role in the nuclear arms race.

Strategic nuclear weapons are intended primarily as part of a doctrine of deterrence by threatening large targets, such as cities or military installations. These are generally delivered by some combination of land-based intercontinental ballistic missiles, sea-based submarine-launched ballistic missiles, and air-based strategic bombers carrying gravity bombs or cruise missiles. The possession of all three is known as a nuclear triad.