I'm no politologist or military strategist, but I'm pretty sure a lot of wars (not all of them) are started so that a nation's government can get better control over their own population. If the state can declare an emergency situation, they can use it to justify cracking down on political dissidents, invasive surveillance, restrincting freedom of speech, etc in the eyes of the public. It can also be used to ramp up nationalism, which works in the ruling class' favour. Pretty sure this is at least part of the reason behind putin and nettanyahu stirring shit up right now.

Stealing is not allowed so you can’t do that. You dont own the whole world.

The problem is that everything is allowed, so they just do that.

Those who don't want to fight in some war - terrorize your population sufficiently and they'll obey, or you can keep them under propaganda pressure and they'll agree.

I would be a coward and flee to a better place.

What if someone wants to take your land, demolish thousand years old churches and fortresses and graveyards, kill all your countrymen they can, all that purely out of hate\envy and because they can?

Would you not want to kill some of those people? Would you not want to prevent such things happening.

Why a country want to attack another country.

A lot of reasons. The most common is a territorial dispute that escalates over time.

The Israel invasion of Gaza is a response to the Al Asqa Flood, which was a response to Israeli encroachment into the Al Asqa Mosque which was a response to Palestinian protests over Israeli treatment of protesters during the 2018 March of Return which was a response to the blah blah blah which was a response to the Israeli Nakba of 1948. And all of that is a consequence of British colonialism in the Middle East, followed by a sloppy (arguably deliberately so) partisan of territories between Arabs and Jews at the end of WW2.

We could play the same game with Ukraine/Russia, which is an extension of a conflict dating back to WW1 and the collapse of the Ottoman Empire. Or we could go to China/Taiwan and talk about the number of times that the island changed hands from early antiquity to the end of the Chinese Civil War.

Stealing is not allowed so you can’t do that.

Telling this to the American First Nations people. Passing the word along to descendants of African and Latin American slaves.

Think of foreign policy as a ladder, and you are the person in charge of your country (or at least their foreign relations). Each rung is a new action you can take to influence the behavior of other countries.

The first step is formal communications. That's easy, you're probably on that step with just about every other nation. The next few rings are all other friendly diplomatic steps, things like opening embassies, making trade agreements, non-aggression pacts, etc.

Now let's say a neighboring country is doing something you don't like. Your nation's grievance with them will fall into one of a few broad categories: they are a threat to your security, they are a threat to your interests, or they are a threat to your honor (meaning your international reputation). Whatever the reason, your job is to change their behavior and none of the previous steps on the ladder have worked, so now you climb higher.

The next rungs are less friendly, but are still diplomatic. These are things like denouncements, cessation of trade, tariffs, and sanctions. At the very top of this set of rungs, you close your embassy and demand they close theirs. You break off most communication. Finally, you tell the whole world why they have wronged you.

Now you've done everything you can diplomatically, but their behavior is still a threat to your security, interest, or honor. How do you change their behavior? There are more rungs on the ladder.

Going all the way back to Sun Tzu, generals have known that their job was to take over when the diplomats failed. This doesn't mean that total war is immediate or inevitable. The military could conduct raids, surgical strikes, or enforce an embargo. Warfare is simply the top rungs of the ladder of foreign policy. Some nations climb it more quickly or willingly than others, but war exists on the same spectrum as diplomacy.

"I am free to move there", saying you are American/western European without saying you are American/western European.

Countries don't attack other countries.

Governments attack other governments.

All of us normal folks who just want to live life are forced along for the ride because we happen to live within the boundaries of a particular government's claimed territory.

Do you know why some countries wanted to attack Germany in the 1930s and 40s?

Sometimes the lesser evil really is war, but much more rarely than war hawks would like to claim. The Roman Empire famously caused strife among their neighbors and used that as an excuse to attack "for the safety of Rome."

To me is it like I am free to move there

Usually countries at war don't let conscription eligible people leave.

Power, ideology and ressources