Israel is transferring civilians to, and building a wall on, land that is not theirs. Does that help?
Name for me one country, other than Israel, that believes this to be untrue.
I don't see anyone doing anything about it. And last time there was a serious try, in 1973, Israel bloodied them pretty well.
When you say "the land is not theirs", to what do you refer? We are not discussing property rights. Property rights are legal rights in individuals and legal entities enforced by government within a sovereign jurisdiction. You "own" your home and effects against claims by others within your soveriegn's jurisdiction who decides what is yours and what is theirs.
Sovereignty itself on the other hand is not a property right. There is no "enforcer" or judge of sovereignty but the soveriegn itself. That's what the word means, supreme, independent. If there were such an enforcer, an entity such as the United States or Israel would not be sovereign entities. Whoever happens to be sovereign of a particular territory is simply that. Other people's opinions, recognitions and documentations are not relevant unless they plan to do something about it. As long as Israel's army stands sovereign on the West Bank and Gaza it is theirs.
There is not any relevance to treaties. Israel could force someone at gunpoint to sign something ratifying the status quo at anytime, much as Santa Ana as a prisoner of war was forced at gunpoint to sign away northern Mexico at Guadalupe Hidalgo. That would not make Israel any more or less sovereign. The Arab states in effect conceded that fact when their armies vacated the area in 1967.
Aside from countries, I am one who thinks Israel should have the whole enchelada for many reasaons and I put whatever tiny influence I have on world affairs behind that position.