The Six-Day War begins, leading to Israel taking control of the Gaza Strip, the Sinai Peninsula, the West Bank, East Jerusalem, and the Golan Heights.
Yes, I know I usually provide links. I can’t find any that seem to be neutral in their point of view. You’ll usually read that this war was started by Israel launching surprise attacks against Egypt and Syria. Yes, that’s true, but it’s a tiny fraction of the story. Israel was merely defending itself and had decided that the “best defense is a good offense”. Arab forces from various countries had been planning this war for months, and likely would have begun their attacks later that day. In fact, the Jordan commander is famously quoted as having said on June 2, “in 3 days we’ll be in Tel-Aviv”. Anyone who tell you that the Israel attack was unjustified is either ignorant of history or lying. Or both.
Anyway, there’s a decent write up in Wikipedia, but I suggest you read it with a high degree of skepticism.
The BBC might be a bit better.
The attack follows a build-up of Arab military forces along the Israeli border.
The Arab states had been preparing to go to war against Israel with Egypt, Jordan and Syria being aided by Iraq, Kuwait, Saudi Arabia, Sudan and Algeria.
On 27 May the President of Egypt, Abdel Nasser, declared: "Our basic objective will be the destruction of Israel. The Arab people want to fight."
The BBC article further points out that this event was a direct result of Palestinian attacks on Israel starting in 1965. Israel’s assault here is not akin to the Japanese attack on Pearl Harbor. A better comparison would be if America had recognized the impending attack sooner and launched a preemptive counterattack on the Japanese Navy on December 6, 1941.