Lenin, Trotsky, and the rest of the Bolsheviks did not initially believe that their regime could survive unless the revolution spread to the rest of Europe. When it became apparent that they were wrong, the regime’s overriding objective turned from promoting revolution to protecting itself. Socialism in one country inevitably evolved into a form of red fascism, with communists in other nations serving more as Soviet agents than active revolutionaries.
It occurred to me yesterday that the story of the Islamic Republic is very similar. Having failed to spread the revolution, the Republic keeps the cause alive by protecting itself. Iranian proxies in places like Lebanon, Syria, and Yemen are just that–they aren’t real revolutionaries.
Will the Iranian regime suffer the same fate as the Soviet Union? In the long run, given its domestic failures and lack of public support, probably. The regime is bound together, however, by an unusual combination of grubby economic self-interest and passionate belief in its divine right to rule. It will not fall until the leadership is divided and doubts its own legitimacy.