Why do liberal internationalists support diplomacy and multilateralism?

Liberal internationalists support diplomacy and multilateralism because they believe international progress—defined as increasing harmonious cooperation between political communities—is achievable. They view these strategies as the most appropriate ways to organize the international system, generally regarding violence as a policy of last resort.1

The support for these approaches is rooted in several key beliefs:

• Institutional Cooperation: Liberal internationalists argue that constructing international institutions, such as the United Nations, helps regulate behavior and strengthen norms.1
• Indivisibility of Interests: Multilateralism is based on the principle that interests are indivisible; for example, in security, peace is treated as a collective good where an attack on one is an attack on all.2
• Economic Interdependence: Proponents argue that free trade creates interdependence, which reduces the likelihood of war by making conflict less beneficial than cooperation.1
• Diffuse Reciprocity: Unlike bilateralism, which often relies on specific, immediate exchanges, multilateralism fosters an expectation of long-term, balanced cooperation among a group of partners.2

By utilizing these frameworks, liberal internationalists aim to move away from the violence and fragmentation of the traditional international system.12