When does it occur?
At times of insecurity, scarcity, etc.
In all ages, whatever the form and name of government, be it monarchy, republic, or democracy, an oligarchy lurks behind the façade; and Roman history, Republican or Imperial, is the history of the governing class. The marshals, diplomats, and financiers of the Revolution may be discerned again in the Republic of Augustus as the ministers and agents of power, the same men but in different garb. They are the government of the New State.
From The Roman Revolution↗ by Ronald Syme, published in 1939.
“Peace cannot be built on exclusivism, absolutism, and intolerance. But neither can it be built on vague liberal slogans and pious programs gestated in the smoke of confabulation. There can be no peace on earth without the kind of inner change that brings man back to his "right mind."”
“The most awful tyranny is that of the proximate Utopia where the last sins are currently being eliminated and where, tomorrow, there will be no more sins because all the sinners will have been wiped out.”
From Gandhi on Non-Violence↗ by Thomas Merton, published in 1965.