CEVAP:

Robert Keohane in his studies, listed three strands of classical liberal theory as (1) commercial liberalism about the pacific effects of trade, (2) democratic liberalism about pacific effects of republican governments, (3) regulatory liberalism about rules and institutions for relations between countries. Joseph Nye has added a fourth one (4) sociological liberalism about the effects of transnational ties on national attitudes and interests (Nye, 1988, 246).