Why did Assyria not last long?

Not at all, Assyria has existed for quite a long time. It arose at the beginning of the 2nd millennium BC. Then it came under the influence of other states of Mesopotamia. In the middle of the 2nd millennium BC, she again was able to become independent. At the beginning of the 1st millennium BC, it was able to turn into the most powerful state of the Ancient East. In fact, Assyria existed from the 15th to the 7th century BC. The final decline of the Assyrian state occurred after the revolt of the Babylonians and Medes.