1. System Level Theories
International Realist Theories:
Classical Realism (power)
Classical (or traditional) Realists believe that there are multiple sources of state behavior and therefore of the causes of war in an anarchical international world.
Neorealism (security)
Neorealism gives realism a stronger social science orientation and seeks to construct a parsimonious realist theory. Whereas Traditional Realists emphasized the pursuit of power as an end in itself, neorealism emphasizes the pursuit of security, with power serving as a means rather than an end.
Defensive Realism
Defensive Realists agree with Neorealists that the anarchic structure of the international system creates potential security threats, but they do not believe that anarchy in itself forces states into conflict and war.
Offensive Realism
Offensive Realists do not doubt the existence of predatory states and predatory leaders, but they argue that the sources of predation can be traced to the structure of the international system, the inherent uncertainty about adversary intentions and anarchy-induced tendencies towards worst-case analysis, without invoking domestic variables.
Neoclassical Realism
Neoclassical Realists recognize the importance of anarchy, argue that material capabilities are the single most important determinant of state strategies and give causal primacy to system structure.
Balance of Power Theories (latent and effective):
The balance of power has been used to refer to the actual distribution of power in the international system, to a distribution of power favorable to one’s own state or to any distribution of power. Also, that no specific balance of power such as unipolar, bipolar or multipolar is more warlike or peaceful than any other. Additionally, when alliance formations change this can lead to the possibility of war.
Hegemonic Theories:
Power Transition Theory
The belief that international systems are frequently dominated by a single powerful state that uses its strength to create a set of political and economic structures and norms of behavior that enhance both the security of the lead state and the stability of the system as a whole.
Long Cycle Theory
A theory about the emergence of global leadership or management of trans-regional interactions such as trade and their impact on war.
2. Dyadic (interactional) Level Theories
Arms Races
A competitive and growing mutual buildup of armaments and military personnel.
International Rivalries
Proximity, or lack thereof, can be a significant cause of war. Another reasonable caveat is that very weak states do not usually take on very strong states.
Steps to War Model
This theory acknowledges that there are many paths to war, and many kinds of war, but it focuses attention on delineating a closely related set of paths to war that involve a series of steps between states that are roughly equal in power.
Bargaining Model of War
The bargaining theory of war begins with the fact that war is costly. War and other forms of violent conflict are inefficient ways to resolve conflicts because they destroy resources that might be distributed among adversaries. In principle, there must be some negotiated settlement short of war that is mutually preferred to fighting.
Economic Interdependence and Conflict
Liberal Theorists have argued that trade and other forms of economic exchange promote peace between states.
Enduring Rivals
This occurs when two Nation States are in disputes over a long period of time.
Contiguous Nation States
This occurs when Nation States share borders.
Window of Opportunity
During certain times a Nation State may be able to prevail against a rival in warfare.
Window of Vulnerability
During certain times a Nation State will no longer be able to prevail against a rival in warfare.
Preventative War
This occurs when war is initiated to prevent another party from acquiring a capability for attacking.
Preemptive War
This begins when a Nation State believes that their rival is about to attack.
Conflict Spirals
The possibility of war grows as more Factors are put in play.
3. State and Society Level Theories
There are a wide range of more specific arguments through which state structures, conditions and processes are said to increase the likelihood of war. Some cultures or ideologies may be particularly warlike.
Marxist-Leninist Theories
This theory posits that war is costly for society in human and economic terms, that any benefits from war fall far short of justifying those costs, and that the capitalist class benefits from war and is ultimately responsible for war.
Military Elites
Warrior elites first came to power in earlier eras when war served a useful function in the protection of empires and states against external predators. Once in power, however, warrior elites create a new military aristocracy and use war and the threat of war to justify their policies and maintain their dominant positions.
Coalitional Models
A focus on the kinds of coalitions that form to gain and maintain power and to conduct domestic and foreign policy.
Diversionary Theory
This is the belief that war is a necessary or convenient means to establish, maintain, or expand the power of a government, party, or class within a state.
Democratic Peace Theory
This theory argues that democracies almost never go to war with each other.
Democratization Theory
The argument that although well-established democratic dyads are peaceful, the process of transition to democracy can be a particularly destabilizing period, and that democratizing states occasionally go to war against other states and even against each other.
4. Civilizational Level Theory
Conflicts along the fault lines between civilizations have been the source of the most prolonged and most violent conflicts in history.
5. Individual Level Theories
An analysis of foreign policy decision-making, which focuses on the individuals and governmental organizations that are empowered to make and implement policies on behalf of the state.
Rational Models
These models conceive of rationality in terms of the maximization of values under constraints and the selection of means that will maximize previously determined goals.
Psychological Models
The tracing of international conflict to the behavior of key individuals in important decision-making roles. These theories focus on the content of individuals’ perceptions, misperceptions and belief systems about world politics, the psychological and cognitive processes through which they acquire information and make decisions, and their personalities and emotional states.
Prospect Theory (risk propensity)
This theory argues that decision-makers tend to think in terms of gains and losses rather than in terms of what they have. In other words, people are more sensitive to changes in power than in the amount of power they possess.
Poliheuristic Theory
This argues that a leader has several policy alternatives or strategies to consider, including taking no action, responding with economic sanctions, withdrawing diplomatic relations, or authorizing a range of military responses.
Crisis Decision-Making
Aspects of decision-making in crises systematically differ from those in more routine decision contexts. Differences exist at the individual, organizational, and small-group levels of decision-making.
6. Organization Level Theories
Organization Process Models
The governmental politics model focuses on politics and bureaucracy within the executive branch of the government, where decisions are ultimately made. A slightly different focus is on key foreign policy agencies, but less on the overtly political dimensions of organizational behavior than on standardized rules and procedures within organizations.
Small Group Level Theories
A theory of small group dynamics that is anchored in individual psychology. It has a number of important implications for decision-making, especially crisis decision-making, on issues of war and peace. Groupthink is a concurrence-seeking tendency within cohesive groups. It is a strong tendency to conform to group norms and reach a policy consensus.
For additional analysis please refer to the Bibliography.