What are the conditions necessary for revolution?

— A ruling class whose power is tenuous because of infighting, and/or presiding over system on the verge of structural collapse.
— The economy no longer works to provide even the most basic survival needs of large sections of the people. The most oppressed are desperate and have nothing to lose.
— A mood among the middle classes of being fed up, angry, disappointed by sliding living standards and unmet expectations, to the point that they would tend to be friendly or neutral if the oppressed rise up.
— An organization that can facilitate, coordinate and direct the outrage of the people toward the real source of their problems, and is capable of leading the kinds of actions necessary to depose the rulers.

I don’t think we’re there yet. But getting closer, especially with the first three.

As for the last condition, could a loose network work, or does it have to be a vanguard party? I can see arguments both ways.