Judea and Samaria are an integral part of Israel despite the military failure by the early Israeli state to hold onto half of Jerusalem, Judea, Samaria and Gaza in 1948/49. The occupation of Judea Samaria and its renaming by Jordan and the occupation of Gaza by Egypt were most certainly illegal. The reversal of that in 1967 led to the present situation and the so-called occupation but it's not a settled legal fact.
The strange part is the only court that has real jurisdiction here is Israel's Supreme court which hasn't done a great job of making the decision. Fortunately there is no globalist supreme court (yet) but all such claims as you make here "everyone agrees" etc, are as shaky as any such globalist consensus line.
And as much as you can hark back to the Carter admin legal opinion, countered by the Reagan admin legal opinion, reversed again by Obama and now again by Trump, you can see this is far from settled law.
The revolutionary thing that Trump and Pompeo seem to be saying this time is that it isn't really for America to decide which is absolutely correct.
If you are truly interested in understanding this on a more than superficial level, this presentation by Eugene Kontorovich is an absolute epic.