The Amarna Tablets found by archaeologists show that there was indeed a growing war with invaders at that time. They were letters written in Babylonian cuneiform to an Egyptian Pharaoh about a group of called the "Apiru" or "Habiru" who scholars believe and has evidence were the Jews. It was a distress call for help.
Among them were letters written in Babylonian cuneiform script to these Pharaohs of Egypt by various kings dwelling in the land of Canaan and Syria, they were written during the time of Moses. They provide the first evidence of the Hebrew tribes entering into the land of Canaan in ancient times.from Bible History Online
Imagine today that one nation is being attacked or threatened to be attacked by another or a group of nations. The president of the threatened country will call a press conference to call for help from its allies or ask for sympathy at the UN. Of course this does not discount the fact if the attacked country is guilty or not. CNN,BBC and other international news media will cover the plea for help with great interest.
The Canaanites have no satellite technology at that time so they sent their plea with stones as letters to the Egyptian Pharaoh.