In early 2019, the Islamic Republic of Iran marked its fortieth anniversary, despite decades of isolation, political pressure, sanctions and war. Observers of its security policies continue to try and make sense of this unlikely endurance. Some view the regime as a purely rational actor, whose national security decisions and military affairs are shaped by the same considerations as in other states. Others believe that it is ideology driving Tehran's strategy. Either way, virtually everyone agrees that the mullahs' policies are fundamentally different from those pursued by their monarchical predecessors.

The rise and fall of the Qajars --Reza Shah, the modernizing strongman -- The last king : Mohammad Reza Pahlavi, the autocratic reformer -- The revolution -- They were expendable : the Iran-Iraq war -- The revolution matures (1988-2001) : consolidation, reconstruction, and reform -- The revolution expands.