Pan-Arabism is an ideology espousing the unification of the countries of North Africa and West Asia from the Atlantic Ocean to the Arabian Sea, referred to as the Arab world. It is closely connected to Arab nationalism, which asserts that the Arabs constitute a single nation. Its popularity was at its height during the 1950s and 1960s. Advocates of pan-Arabism have often espoused socialist principles and strongly opposed Western political involvement in the Arab world. It also sought to empower Arab states from outside forces by forming alliances and, to a lesser extent, economic co-operation.