Perspectives on International Relations: Power, Institutions, and Ideas shows students new to the field how theories (perspectives) of international affairs—realism, liberalism, constructivism (identity), and critical theory—play a decisive role in explaining every-day debates about world affairs. Why, for example, do politicians and political scientists disagree about the causes of the ongoing conflict in Syria, even though they all have the same facts? Or, why do policymakers disagree about how to deal with North Korea when they are all equally well informed? The new Sixth Edition of this best-seller includes updates on Brexit, the rise of Donald Trump and other populist leaders, and continuing developments for ISIS, Syria, and Russia.