While Liberalism acknowledges the difficulties for peace and cooperation in the international system identified by Structural Realism, it also claims that these goals are attainable. What makes Liberalism more optimistic than Structural Realism?

Liberalism believes that States at times pursue total gains thus they have incentives to cooperate in as much as they have common interests.

Explanation:

Liberalism is a political and ethical philosophy that is based on liberty, consent of the governed and fairness before the law

Liberalism wanted to restore the norms of hereditary privilege, a state religion, and complete monarchy, the divine right of customary kings and traditional conservatism with some bit of democracy and the rule of law.