the land doesn't belong to Israel.
Yes it does. They were attacked and beat their attackers and took the spoils of war.
c'est la vie...
There is a related question I've brought up more than once:
Is Breslau occupied by the Poles?There are consequences to losing wars.
But I do think I understand the position of many of those who say that the "West Bank" is Palestinian land occupied by Israel but Breslau is not German land occupied by Poland. Many people believe in some concept of "international law" which means that these kinds of questions are answered by certain "international bodies" (often offshoots of the United Nations). So the West Bank is occupied because certain "international bodies" say so, and Breslau isn't occupied because there aren't "international bodies" who say it is. I find this to be a scary way to look at the world, outsourcing one's judgement to "international bodies" -- but many people find it more comfortable than thinking things through for themselves.
I don't know enough about Breslau to have a qualified opinion. What are the circumstances that would lead you to question its status as occupied or not? Does Germany contest the land?
Does the civilian population express a German identity rather than Polish? Apparently not. It's Poland's 4th biggest city, it doesn't have a significant German minority and people living there have no interest in becoming a part of Germany.
If we discuss moving the borders and giving everyone back what was taken we'll face a big problem: the restoration point (date).
Your example - Poland fits here perfectly because in 1939 a large part of today's Ukraine and Belarus belonged to them, so you'd have to give back to the Germans but take from someone else.
I'm just trying to understand why anyone would ask if it's occupied. If no one is even seriously questioning it's status, the analogy JJ tried to draw between Breslau and Palestine isn't valid. Perhaps then the reason no international body has deemed Breslau occupied territory is because there's no basis for it because nobody is disputing the territory today.
I can explain why I ask. No analogy is perfect, of course, but in many ways the status of Wrocław (which I'm provocatively referring to as Breslau) mirrors the status of the land west of the Jordan river.
As Bryant Coleman pointed out, Breslau was part of Germany and was ethnically overwhelmingly German in 1900. It continued to be a major German city until after WWII. As part of the post-war reparations, this part of Germany was given to Poland. The reason it is now called Wrocław and is overwhelmingly Polish is simply because the German population was essentially expelled after WWII.
This happened in the late 1940s, the same time period in which the British mandate for Transjordan ended and the state of Israel declared independence. This is the same period of time in which many Palestinians left their homes in the new state of Israel. (Those against Israel would say they were "expelled" while those pro-Israel point to the fact that neighboring Arab countries warned Palestinians to leave in advance of Arab countries going to war with the newly declared state of Israel.)
In the late 1940s, Germans lost Breslau to Poland and part of that involved a significant population displacement. It happened as a result of losing WWII. As I've pointed out before, significant Palestinian leaders were allied with Hitler. In this sense, at least, they were also on the losing side of WWII. The two cases are quite similar.
The situations are also different. There is no outcry to return Wrocław (Breslau) to Germany. There certainly could be. Germans unhappy with the outcome of WWII could start hijacking airplanes and bombing restaraunts. One of their demands could be the return of Breslau. The fact that this isn't happening is largely due to the vast majority of Germans being (apparently) reasonable people who accept the loss of WWII and its consequences. But lets suppose some small minority of German neo-Nazis started committing acts of terrorism to try and return Breslau to Germany. Would international bodies start taking the case more seriously? I doubt it. First of all, the German authorities would obviously say that Wrocław is a Polish city and take steps to catch and imprison the neo-Nazi terrorists. The neo-Nazi terrorists would not be the "militant arm" of any political force in today's German government.
In essence, terrorist acts by German neo-Nazis would be
counterproductive if the goal were the return Breslau to Germany.
Why have terrorist attacks by Palestinians resulted in their demands being taken more seriously? I think this is largely due to prejudice against Jews, but also prejudice against Arabs. Of course, many people (including many Jews) who have a problem with Jews, reflexively side against the Jews. In addition, whereas Germans are expected to be civilized, many people do not have the same expectations of Arabs. This is itself a form of bigotry. When Palestinian Arabs commit terrible acts of terrorism, instead of seeing it as something that should undermine their cause, it is seen by many people as the result of throwing someone in a lion's cage. No one's surprised when a lion kills and eats someone. It's a lion. I would prefer it if Arabs were held to the same standards as, say, Germans. But they aren't.
Another very important difference is that Germany explicitly agreed to the reparations at the end of WWII. The conflict is over. This is not the case for the middle east conflict. However, this implies that the conflict is, in fact, ongoing. The fact that Israel takes a series of military measures including bombing campaigns, blockades and checkpoints is hardly surprising when one accepts that they are in an ongoing conflict. The fact that one of the natural conclusions of this conflict would be the destruction of Israel and the murder of the millions of Jews there actually makes Israel's actions seem quite measured.