In international relations, the security dilemma (also referred to as the spiral model) is when the increase in one state's security (such as increasing its military strength) leads other states to fear for their own security (because they do not know whether or not the security-increasing state intends to use its growing military for offensive purposes). Consequently, security-increasing measures can lead to tensions, escalation or conflict with one or more other parties, producing an outcome which no party truly desires; a political instance of the prisoner's dilemma.

The security dilemma is particularly intense in situations when (1) it is hard to distinguish offensive weapons from defensive weapons, and (2) offense has the advantage in any conflict over defense. The security dilemma is a key concept in international relations theory, in particular among realist scholars to explain how security-seeking states can end up in conflict. identified the following core components between interpretations of the security dilemma by Herbert Butterfield, John H. Herz, and Robert Jervis:

{| class="wikitable"

|+

!Aspect of the security dilemma

!Butterfield

!Herz

!Jervis

|-

|Ultimate source is anarchy

|X

|✓

|✓

|-

|Uncertainty over others' intentions

|✓

|✓

|✓

|-

|Mutual fear

|✓

|✓

|✓

|-

|Lack of malign intentions

|✓, inconsistently

|✓

|✓

|-

|Power competition

|Not explicitly

|✓

|✓

|-

|Spiral-like situation

|Not explicitly

|✓

|✓

|-

|Unintended tragic results

|✓

|✓

|✓

|-

|Unintended (and partially self-defeating) results

|Not explicitly

|✓

|✓

|-

|Regulators

|Only psychological factors emphasized

|Not emphasized

|Both material and

psychological

factors

|-

|Universal/conditional?

|Universal

|Conditional

|Conditional

|-

|Important cause of war?

|✓

|✓

|Close to ✓

|-

|Cause of all war?

|✓

|X

|X

|}

Butterfield viewed the security dilemma as the root cause of all war, but he did not view anarchy as being the ultimate source of the security dilemma. Instead he attributed the source to fear and the "universal sin" of humanity — that humanity can commit evil. Herz and Jervis did not view the security dilemma as being the root cause of all war. A counterexample frequently given is the Second World War, where there was no dilemma over war with a malign Nazi Germany. The security dilemma explains why security-seeking (as opposed to non-security seeking) states could end up in conflict, even though they have benign intentions. In situations where the defense has the advantage, security-seeking states can afford to focus strictly on their defense without as much fear of being attacked. Security-seeking states can also signal benign intentions without adversely affecting their own security. The conclusion from defensive realism is that in some circumstances states can escape the security dilemma.

Offensive realism

Offensive realism and defensive realism are variants of structural realism. They share the basic beliefs of survivalism, statism (state as the primary unit), self-help and anarchy. (See international relations theory.) However, contrary to defensive realism, offensive realism regards states as aggressive power maximizers and not as security maximizers. According to Mearsheimer, though achieving hegemony by any state is not likely in today's international system, there is no such thing as a status quo and "the world is condemned to perpetual great power competition". In other words, defensive realism contends that security can be balanced in some cases and that the security dilemma is escapable. While offensive realists do not disagree, they do not agree fully with the defensive view instead contending that if states can gain an advantage over other states then they will do so. In short, since states want to maximize their power in this anarchic system and since states cannot trust one another, the security dilemma is inescapable.

Offensive realists dispute that the offense-defense is a major determinant of state behavior, arguing the concept is vague, that offense and defense cannot be distinguished, that the offense-defense balance does not vary significantly over time, perceptions among leaders of the offense-defense balance varies even within the same time periods, and attackers and defender can use most types of weapons to achieve their goals.

The deterrence model is contrary to the spiral model, but also purports to explain war. While the spiral model presumes that states are fearful of each other, the deterrence model is based on the belief that states are greedy.

  • Preventing armed attack against a country's own territory ("direct deterrence")
  • Preventing armed attack against the territory of another country ("extended deterrence")
  • Using deterrence against a short-term threat of attack ("immediate deterrence")

Under some circumstances attempts at deterrence can "backfire" when a potential attacker misinterprets the state's deterrence measures as a "prelude to offensive measures". In such cases the security dilemma can arise generating perceptions of a "first strike advantage".

Chain ganging

In a multipolar world, alliance security is interconnected. When one ally decides to participate in war, it pulls its alliance partners into the war too, which is referred to as chain ganging. If the partner does not participate in the war fully, it will endanger the security of its ally. For example, in World War I, to the alliance between Austria-Hungary and Germany, according to Waltz, did this: "If Austria-Hungary marched, Germany had to follow: the dissolution of the Austro-Hungarian Empire would have left Germany alone in the middle of Europe". On the other side, if "France marched, Russia had to follow; a German victory over France would be a defeat for Russia. And so it was all around the vicious circle, because the defeat or defection of a major alliance would have shaken the balance, each alliance partner would have shaken the balance, each state was constrained to adjust its strategy".

Buck passing

In the face of a rising threat, balancing alignments fail to form in a timely fashion as states try to freeride on other states. States might do so to avoid the expense of war for themselves. For example, to use Waltz's example, in World War II, the French Foreign Minister told the British Prime Minister that Britain was justified in taking "the lead in opposing Germany" when the Nazis had taken over the Rhineland, but as "the German threat grew", France and Britain hoped that Germany and the Soviet Union "would balance each other off or fight to the finish. Uncertainties about... who will gain or lose from the action of other states accelerate as number of states increases".

Criticisms and responses

According to Alexander Wendt, "Security dilemmas are not given by anarchy or nature" but, rather, are "a social structure composed of intersubjective understandings in which states are so distrustful that they make worst-case assumptions about each other's intentions". Jennifer Mitzen mirrors Wendt's critique, arguing that the security dilemma can be caused and maintained by the pursuit for ontological security rather than rationalist security-seeking.

Glaser argues that Wendt mischaracterised the security dilemma. "Wendt is using the security dilemma to describe the result of states' interaction whereas Jervis and the literature he has spawned use the security dilemma to refer to a situation created by the material conditions facing states, such as geography and prevailing technology". According to Wendt because the security dilemma is the result of one state's interaction with another, a state can adopt policies which hinder the security dilemma. Glaser blames Wendt for "exaggerating the extent to which structural realism calls for competitive policies and, therefore, the extent to which it leads to security dilemmas". Glaser argues that though offensive realists presume that in an international system a state has to compete for power, the security dilemma is a concept mainly used by defensive realists and according to defensive realists it is beneficial for nations to cooperate under certain circumstances.

Another mode of criticism of the security dilemma concept is to question the validity of the offence-defense balance. Since weapons of offense and of defense are the same, how can the distinction between the two be connected with a state's intentions? As a result, critics have questioned whether the offense-defense balance can be used as a variable in explaining international conflicts.

According to Charles Glaser, criticisms of the offense-defense balance are based on two misunderstandings. First, the sameness or difference of offensive weapons compared with defensive weapons does not impact the offense-defense balance itself. Offense-defense theory assumes that both parties in conflict will use those weapons that suit their strategy and goals. Second, whether both states involved in the conflict have some common weapons between them is the wrong question to ask in seeking to understand the offense-defense balance. Instead, critics should focus on the influence or net effect of weapons used in the conflict. According to Glaser, "Distinguishability should be defined by comparative net assessment" or the comparison of the balance of offense-defense when both sides use weapons versus when neither side is using weapons.