The 1979 Iranian Revolution was achieved by the evil forces of Islamism and Marxism...
ISLAMO-LEFTISM: THE UNHOLY ALLIANCE
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While Western leftists make no similar religious references, they do contend, like radical Islamists, that the United States is determined to overrun other nations and dominate the world.
Radical Islam seeks purification and "social justice" by means of jihad, or holy war, whose highest ideal is martyrdom achieved while attempting to conquer an evil worldly power such as the United States, the Great Satan (and Israel, the Little Satan). The radical Islamist's ultimate goal is to subdue the "infidel" nations and therein institute sharia, or Islamic law, so as to redeem the world for Allah.
The radical left, similarly, advocates revolution as the means of achieving its ends -- eliminating capitalism and creating a socialist paradise on earth.
While Islamic radicals seek to purge the world of heresies and of the infidels who practice them, leftist radicals seek to purge society's collective "soul" of the vices allegedly spawned by capitalism -- those being racism, sexism, imperialism, and greed.
Just as Islamic radicals aim to impose their religion on the rest of the world in a totalitarian fashion requiring unwavering obedience, so do radical leftists strive to create an omnipotent socialist state that will control every aspect of daily life and will impose a universal brand of "social justice" on all mankind.
Central to both radical Islam and the radical Western left is an inclination to overthrow the existing order by any means necessary, so as to create a paradise on earth. Leftists may find the bigotry and intolerance of Islamic radicals repugnant, but their desire to rid the world of U.S. "imperialism" and capitalism overrides this revulsion and beckons them to forge the unholy alliance.