Answer: Realists: Selfish way that the countries define their power
Liberals: Decisions taking on everyone´s benefit.
Explanation: For one of the main theorists of realism, Hans Morgenthau, points to the national interest as the compass that should guide the leaders and source of legitimacy of the foreign policy of the state. For this author, the national interest of a nation can only defined on terms of survival and power.
Since liberalism, the national interests of the states become in a large part of the situations, common and shared by various states. Therefore, the national interests should not be promoted without talking into account the effects that will be caused to others.