Why did Assyria disintegrate?

612 BC was the last year of the unified state in Assyria. After that, it was destroyed by nomadic tribes, Medes and Babylonians. They organized a large-scale uprising, which, in the conditions of turmoil in Assyria, negatively affected the state structure. In general, the disintegration of the state began to be observed in the period after the death of the ruler Ashurbanipar. After his fruitful reign, turmoil and fragmentation began in the country. They were accompanied by external aggression, which destroyed the country.