Tribal societies manage envy in two ways.
1) They maintain a small elite which is insulated from the masses (by religious or social convention and control of organized violence, ie power) and the masses are maintained at relatively similar levels of poverty. This diminishes the disparities which fuel envy.
2) They direct the envy outward toward other tribes. This is one of the reasons the fantasy of the noble savage who lives in peaceful harmony with the environment and with others, is such nonsense. Tribes cannot be pacifistic; they must be war-like since their internal cohesion relies on externalizing their aggression.
From almost the time Abraham entered into the Covenant with God, the Jew has functioned as the ideal "other" tribe upon which to project one's envy.
Using Jews as a way to manage envy has continued to be the modus operandi of the Arab world. If anything, the problem had become exponentially more difficult with the founding of the state of Israel. Since the founding of Israel, the disparity between the accomplishments of the tiny Jewish minority in their midst, and the enormous mass of Arab and Islamic peoples surrounding them, has grown by leaps and bounds. This despite the Muslim world being blessed with the possession of a large percentage of the world's energy reserves.
In the West, communism was an attempt to rescue the tribal system from the growing disparities of unconstrained capitalism, which threatened to increase envy to such a degree as to threaten the existing order. Communism would have worked if it did not have the capitalist success by which to compare itself. After all, what was communism, in practice, except the establishment of a new tribal society based on a small cadre of elites monopolizing assets while enabling shared deprivation for the masses (with the Utopian promise of abundant goods and services for everyone just as soon as the system could become established and start to work properly.) The purest form of communism arguably was the Khmer Rouge, who were so committed to equality for everyone that anyone with any special skills was put to death. Death certainly puts an end to envy; everyone is exactly equal once dead.
The Welfare State, Socialism-lite, has been the democratic compromise response to the tendency of unbridled capitalism to lead to new elites with monopolies of power and goods; by offering a safety net to all, all could be encouraged to strive for riches. This allowed "normal" envy to be managed by the possibility of achieving success for most people. As a corollary, wealthy liberals often feel the need to pursue class based policies in order to minimize the imagined envy of the poor for what they have. If they feel they are not truly deserving of their wealth (because it was inherited, or because they were privileged or lucky) it makes them even more fearful and determined.
This is precisely where the left and the Islamists intersect. They both believe in managing envy by using the tribal template. They are both terrified of a future in which they cannot compete and in which they may lose their privileges. They have differing, and mutually exclusive, ideologies, but they agree on the basic problem and the basic solution, which is why so many on the far left have found a home in alliance with radical Islam...