Final answer:
Liberal theories of international relations differ from neo-realism in that they emphasize collaboration and institutions for collective security, whereas neo-realism focuses on the international system's structure influencing state behavior.
Step-by-step explanation:
Liberal theories of international relations and neo-realism can be distinguished by their different approaches and assumptions regarding state behavior and the international system's structure. The liberal theory posits that states are part of a larger system and collaborate with various institutions to benefit all, while neo-realism, also known as structural realism, focuses on the anarchic structure of the international system where states act to maintain their survival.
Under liberal theory, states are seen to work together to achieve collective security and are motivated by the best interest of the international system, with domestic rules and institutions constraining their actions. Neo-realism, however, while also seeing states as the primary actors, suggests that it is the international system's structure that dictates state behavior. NATO is a notable example of liberal international theory in practice, where member states collectively agree to provide security.