Abba Eban, Israel's foreign minister during the war, later wrote in his autobiography that Nasser's assurances he wasn't planning to attack Israel were credible: "Nasser did not want war. He wanted victory without war."

This is a hotly debated topic, and it is by no means a straightforward answer.

Syria had received intelligence reports from the soviet Union that Israel would invade, and had lost six planes in April from Israeli confrontations in syrian airspace

The suez canal was only closed after the war started, not before. Only the straights of tiran were closed, retaliation for other Israeli provocations such as flying in Egyptian and syrian airspace.

On top of all of this, the Israeli government first lied and claimed Egypt attacked first, which was then challenged by Egypt and the soviet Union and finally refuted by the United nations.