What caused the societal collapse and destruction of cities 3200 years ago?

[lpetrich]

•  Late Bronze Age collapse
• What Destroyed All of the Major Bronze Age Cities? | by Grant Piper | History of Yesterday | Medium - "A mysterious apocalypse brought down nearly all of human civilization three thousand years ago"
• Bronze Age Collapse - Ancient History Encyclopedia
• The Bronze Age Collapse - The Human Journey
• The influence of climatic change on the Late Bronze Age Collapse and the Greek Dark Ages - ScienceDirect
• 3.2 ka BP Megadrought and the Late Bronze Age Collapse - Oxford Scholarship

Some 3,200 years ago, humanity suffered a great catastrophe. Nearly every city was destroyed near the eastern Mediterranean Sea from Greece to Gaza. Temple-palaces were destroyed and society was reduced to small villages. Literacy was lost over most of this area.

What caused it? Earthquakes? Droughts? Rebellions? "Sea People" invaders? Paleoclimate research has revealed evidence of a "megadrought" in the eastern Mediterranean at this time. This drought would then have provoked famines, rebellions, and migrations, leading to destruction of cities. The Mycenean palace centers burned down, and their burning preserved a large number of tablets with accounting records on them. They were written in Greek using the Linear B script. But Linear B disappeared with these palace centers, and Greeks has to re-learn writing.

Egypt and Mesopotamia survived this catastrophe, and Egyptians have left us the most detailed surviving records of it.

A few centuries before, Egypt built an empire in the Levant, and at first, it seemed secure. At least if we are to believe Pharaoh Merneptah's bragging about the successes of his armies:  Merneptah Stele - about 1280 BCE

The princes are prostrate, saying, "Peace!"
Not one is raising his head among the Nine Bows.
Now that Tehenu (Libya) has come to ruin,
Hatti is pacified;
The Canaan has been plundered into every sort of woe:
Ashkelon has been overcome;
Gezer has been captured;
Yano'am is made non-existent.
Israel is laid waste and his seed is not;
Hurru is become a widow because of Egypt.

Then a big  Battle of the Delta - about 1175 BCE - Egyptians fought the  Sea Peoples as they tried to invade the Nile Delta.

A big victory in Palestine, then a big victory in the Nile Delta. Something doesn't quite add up. In any case, Egypt's New-Kingdom Levantine empire was gone.