There are many different schools of thought on the nature of international relations; of these realism and liberalism are the most prominent. Each defines the state of the world in different ways. The ideology a person subscribes to will be indicative of how they think foreign policy should be carried out.
The main tenants of realism are outlined in the table below:
|state of the world||anarchic|
|goals of actors||security-seeking|
The following is a breakdown of the above tenants:
a flawed and aggressive human nature
Realists believe that humans are inherently conflictual. It's a very Hobbesian viewpoint. Cooperation is not likely, and the only way to ensure your safety is to carry a bigger stick than all the other guys.
According to realists, the world is a state of anarchy, meaning that there is not a world-wide governing power. Years ago, this statement was accurate, before bodies like the United Nations and European Union, but even with their existence, realists would argue that they are not effective, and will likely fail. This claim is supported by the limited enforcement power of most international governmental bodies. Without a world government, the interactions between states occur in a space of ungoverned chaos. This breeds uncertainty - a state will not know for sure what the intentions of another state are.
rational state actors
Realists believe that only states are actors in international relations; intergovernmental organizations, international non-governmental organizations, and non-state violent actors are not usually relevant. They consider states to be rational actors, meaning that the choices they make will be logical and, therefore, predictable.
In the realist school of thought, all states are theoretically maximizing their security, which is done by maximizing relative power. For example, in a two-state system, if State A has a power level of 60 units and State B has a power level of 50 units, then State A would win in a war, thereby making them more secure. State A will want to increase their 10 unit positive differential and State B will want to overcome the negative 10 unit differential. Of course power is not so simply measured - realists think power is mainly comprised on military might - how many tanks, aircraft carries, soldiers, etc. that a state owns. Realists don't consider economic relative power to be of particular importance, other than how it can increase the military capacity.
the security dilemma
The security dilemma says that because states do not know the intentions of other states, any build up in military strength, whether offensive or defensive, will be considered a threat. It will result in the other state also building up military strength, which in turn threatens the first state. It's a cycle, or, an arms race.
Some scholars say that the security dilemma can be mitigated by choosing defensive weapons that cannot have an offensive purpose. For example, building an radar system to detect incoming missiles in support of existing anti-missile infrastructure is less threatening than building fighter planes, which can be used for defensive or offensive purposes.
The main tenants of liberalism are outlined in the table below:
|state of the world||anarchy is not inevitable|
international non-governmental organizations (including corporations)
|goals of actors||peace-seeking|
|implication||democratic peace theory;
economic interdependence creates peace
The following is a breakdown of the above tenants:
a cooperative human nature
Liberal scholars believe that human nature is inherently good, and that not only is cooperation possible, it is probable. Cooperation between states can lead to a peaceful world.
anarchy is not inevitable
While the world may naturally be anarchic, there are ways to decrease the puissance of anarchy. A world government is an extreme example of a way to combat anarchy, but high degrees of cooperation between states in the way of alliances and intergovernmental organizations would also be effective in decreasing anarchy, according to liberals.
states are not the only actors
Liberals consider states to have an important role in international relations, but they are not the only actors that have sway. Organizations that increase cooperation and interdependence - such as intergovernmental organizations and international non-governmental organizations - are also vitally important, as cooperation and interdependence will lead to more peaceful times.
In the liberalism school of thought, the ultimate goal is not security, but rather increasing peace through cooperation and interdependency.
the paths to peace
Democracy and economic interdependence are the two main characteristics of peaceful states, according to liberalism. Democratic Peace Theory states that when two states are democratic, they will not engage in wars or other aggressive actions. The rationale is that two democracies are unlikely to view each other as hostile, unlike a democracy and an authoritarian state. Additionally, democratically elected leaders are responsible to their constituents, who would likely not want to engage in war. Democratic nations also tend to trade with other democratic nations, which increases economic interdependence. Regardless of the form of government of two states that trade together, they are reliant on their other for their economic wellbeing. This reliance dissuades the states from engaging in war with each other. Both of these theories, however, have been questioned by scholars who do not think causation has been proved, only correlation.