めつぼう滅亡metsubou
1.
The complete destruction or disappearance of a civilization or cultural entity, often resulting in significant historical loss.
2.
The process through which a powerful nation or organization falls into decline and ultimately ceases to exist, marked by internal strife or external pressures.
3.
The state in which a society or political system not only fails to thrive but also collapses entirely, leading to a profound transformation in the historical landscape.
4.
An event or series of events that culminate in the end of a prominent institution or regime, characterized by upheaval, chaos, and irreversible change.
Example:
仮に核戦争が起こったとすれば、人類は滅亡するだろう。