What two opposing forces are fundamentally engaged in a tug-of-war governing the star formation rate?

Answer

Inward pull of gravity versus outward push of various pressures

The physics hinges on gravity attempting to compress matter inward versus the outward push provided by resisting pressures like thermal and magnetic forces.

What two opposing forces are fundamentally engaged in a tug-of-war governing the star formation rate?
galaxiesastronomyratestarsstar formation