Josh W. answered • 03/15/23
UPenn Writing Tutor, John Locke and College Application Essay Expert
Realists prioritize the fundamental global condition of anarchy, meaning that states are the highest-level actor in the international system. Within states, the government provides the social good of security by maintaining a military and a police force; realists claim there is no such analogous body in the international system, so states are responsible for their own security. Relative power advantage is the only way to achieve security, and in addition to economic success and military development, alliances are also a key tool to "balance" larger competitors and gain undue influence. Enter NATO. Realists believe states joined NATO (and sacrificed some of their freedom and resources) due to this "balancing" granted by NATO (especially for small states in the immediate or close vicinity of the USSR).
There are a few more varieties of liberalism than realism, but fundamentally, Liberals believe in a dual mandate of inalienable human rights and freedom. Liberals argue that rights are inherent regardless of power, whereas realists argue that rights are "secured" (a state only has a right to that which it can defend). NATO itself is a democratic multilateral institution, a form liberals love (states coming together rationally and equally to act in everyone's best interest.) Liberalism's Democratic Peace Theory explains this well: democracies joined NATO because institutions can better secure fundamental rights for those living under Soviet oppression, and because they rationally believe democratic freedom and market capitalism is better than communism. And under neoliberalism, spreading democracy and market values (liberalism is often inextricably tied to free-market economics) is both a fundamental moral good and strategically beneficial.
Constructivists believe state identity determines state actions, rather than anarchy & power (realists) or inalienable human rights (liberals). Norms, disseminated by international institutions or other states, "peer pressure" states into certain patterns of action, which are reinforced depending on the collective meaning a state makes while acting in accordance with a norm. Individual state interpretation of facts is critical for constructivists, so a constructivist wouldn't really ask "why states joined NATO," but would look through the history and resultant worldview of each state, assess the relevant pressuring norms and legal regimes, and make a tailored assessment of each state's interpretation of the global system at that point in time, and how that interpretation fueled the desire to join NATO.
For each philosophy of IR, states have stayed in NATO because the initial philosophical reasoning is still relevant. For Realists, the fall of the USSR didn't end the global condition of anarchy, and the ongoing invasion of Ukraine is a great example of the vulnerabilities non-NATO countries tolerate. For Liberals, the fall of the USSR represented a phenomenal opportunity to bring market democracy to the newly independent countries (obviously not totally successful - see Hungary & Belarus for good modern examples). However, this worked partially, and die-hard liberals/neoliberals are still trying to creatively export liberal values. As an international institution, NATO is a prime mechanism by which these values can be transmitted. For Constructivists, while each state has their own reasoning for staying in NATO based on their own interpretations of history & the current state of the world, two particularly strong norms in state psychology are prominence (copying the actions of a powerful state to gain respect & benefits from the strong state) and peer effect (adopting certain actions to prove loyalty to a group). Since NATO membership has serious benefits (famously, Article 5 collective defense), acting loyally to NATO and in compliance with its mandate and liberal democratic values is a positively reinforced norm.
