It’s important to separate out the government from the people, especially as it pertains to governments that don’t listen to their population and don’t have overwhelming support. Neither government is good. Most of the civilians from both sides are perfectly decent, though a number of them are misguided.

It’s really impossible to simplify it, but I’ll give it a shot with a quick timeline:

• ~1200 BCE: Several unrelated tribes of people group together to become what we now call Jews or Hebrews or ancient Israelites. How this happened and exactly when is disputed, and is significantly muddied by their own mythology.
• ~600 BCE: The first major expulsion of Jews from areas variously known through time as Palestine, Israel, Jerusalem, and many others.
• ~538 BCE: Jews are allowed to return (until next time).
• ~538 BCE through 1896 CE: For the sake of brevity, let’s just say Jewish people rarely had real control over this land and were consistently persecuted and/or expelled from wherever they were.
• 1896 CE: Theodor Herzl writes “The Jewish State” and births the modern Zionist movement, claiming Jews have a right to Israel primarily on religious basis. He approaches world leaders saying as such and finds little traction.
• 1920: Britain takes control of the area now called Mandatory Palestine.
• 1941-1945: The Holocaust. I assume no additional information needed.
• 1945-1948: The Holocaust gives significant weight to Zionists’ arguments that Jewish people need their own country. As many Jews have already been emigrating there (known as “Aliyah” or Jewish emigration to the promised land) since Zionism took hold, the powers that be (UK and US primarily) already have control of the area (still Mandatory Palestine), and a desire to maintain control of the area, they decide to give most of that land to the Jews and call it Israel.
• 1948: Israel is officially recognized by the United States, its primary backer today. As part of this recognition, Israel and its allies committed what is commonly known as “The Nakba.” A huge number of Palestinians were killed, injured, jailed, or forcibly removed from the area.
• 1948: Arab-Israeli War. The Arab countries unite to fight the new state of Israel. This, as with most wars, is primarily because of power. The don’t want the West to be controlling the region. The Arabs lose, but nobody loses more than Palestine.
• 1948: Palestinian attacks on Israel start. I don’t have anywhere else to put this, but know that the end of the Arab-Israeli War didn’t end Palestinians fighting for their land and independence. They will continue to do so by any means available to them.
• 1956: Suez Crisis. Israel and its backers invade and militarily occupy part of Egypt and take control of the Suez canal because Egypt decided to nationalize it. This war is transparent in its goal for power.
• 1967: Six Day War. Israel invades a variety of areas that it borders, including land owned by Egypt, Jordan, and Syria. Palestine would be listed as well if it were recognized as a state. They’re successful in only six days. Notable areas you may have heard of that were militarily acquired by Israel at this time are the West Bank, Gaza, and Golan Heights. Israel still retains control over these conquered areas.
• 1973: Yom Kippur War. Arab states attack to try to get back the land lost in the Six Day War. Israeli victory.
• 1978: Camp David Accords. Israel agrees to give some land back in return for being recognized by Egypt as a state. Sedat, the Egyptian leader, would be assassinated in part because of this action.
• 1987–1993: First Intifada. More organized and wide-scale Palestinian insurgency than we’ve seen before. Palestinians are fighting for their independence and their land. The insurgency is suppressed.
• 2000–2005: Second Intifada. Same reasons and result as the first.
• 2006-current: Much like the intifadas, there’s a lot to say here, but for the sake of brevity (lol too late) the Palestinian attacks that started in 1948 continue to this day. Israel intermittently declares various wars with the claim that they’re rooting out terrorists, Hamas, Hezbollah, and more.

This leaves out a lot. It’s just not possible to condense it. But (mostly) off the top of my head, that’s what I’d consider most of the most important bits.

The way I see it, whether or not you think Israel is “the good guys” largely hinges on whether or not you think Jews have a right to the land of Israel, and whether or not you think that claim was executed in a humane way.

I would compare it to the Native Americans - were the Americans of that time period the “good guys”? In my opinion, absolutely not. Were the Native Americans wrong for defending their land? Again, absolutely not. Were they wrong for attacking innocent civilians in retribution (for their land being taken, their own innocent civilians being killed, a genocide in progress)? Maybe, but it’s also understandable that when you’re working from a position of basically zero power against a behemoth, you can’t fight the way the behemoth fights, or you’re going to lose.

The way I see it, the Palestinian people just want a place to live and develop, and nobody’s giving them a way out, so they’re trying anything and everything they can.