~not the user who you were replying to~

if a whole nation would be moved onto my homeland, and from now on it wouldn’t be my homeland, but theirs. Is that how it worked?

The thing is... that describes the situation of multiple existing countries (USA, ahem) and, if you go back enough in history, probably almost every country in the world.

Simply determining which group is the single "native" people to that area is difficult. So many groups have inhabited, controlled, and fought over the region for millennia.

I agree with Horsey. The more I read about the conflict, and the farther back I go in history, the messier it all gets. I will be amazed if someone can write up a good ELI5 on this particular topic.

The thing is, the land itself is not the issue, there is enough land there. Rather, both parties have vastly different political ideals (and religions) and the people from neighbouring countries heavily disagree with Isreals politics.

After WW2, Great Britain gave most of the land to the surrounding countries (as far as I understand) but reserved some land for what is now known as Israel for Jews to be able to form a state. However, this did not sit well with the overwhelmingly muslim countries around it.

Good to know: Whether Palestine is a country depends on who you ask. Most countries in North America, Central/Western Europe and Oceania (Australia etc.) DONT consider Palestina a country while countries in South America, Africa and Asia overwhelmingly DO recognize it as a country (there are exceptions).

“If a whole nation would be moved into my homeland, and from now on it wouldn’t be my homeland”

Yes, this is your ELI5. Majorities come and go. Governments come and go. I’ll give you two examples right next door to Israel:

1. Egypt was a dynastic system, then Geek, then Roman, then Christian nation then an Arab nation beginning in the 7th century. During each of the periods, a particular ethnicity did exactly the above: they moved in and became the majority. There was a point where it was overwhelmingly correct to call Egypt any one of the above after dynastic rule concluded. Today, Egypt is a Muslim majority country, but if for some reason christians poured in (the British kindof started to do this in the early 19th-20th century in the protectorate period) it would, at some point, become christian.

2. Constantinople was a Christian capitol city for centuries until the Ottoman conquest in 1453. The city was renamed Instanbul in 1928, but wasn’t recognized as such until a year later in 1929.

The takeaway from all this is that land changes hands in various ways. It’s the point at which the definition of a land changes that is sometimes controversial until a kind of revolution takes place.