The uprisings across the Arab world are becoming more complex and variable as they enter their second year. This makes it all the more important to identify their main dynamics, says Volker Perthes.

The attacks of 11 September 2001 did not, after all, transform the world. But they did propel the United States into a unilateral and regime-change moment - and pose a more enduring challenge both to American and European conceptions of security and stability, says Volker Perthes.

The path to a resolution of Iran’s internal political crisis and its international nuclear confrontation is uncertain. Volker Perthes outlines four possible ways forward.