Of course, Israel can declare its border with the Pals unilaterally. It just doesn't want to, because it prefers the current state of uncertainty. The only unilaterally declared border the world will recognise is the Green Line and Israel is greedy for more than that. But it doesn't want to actually annex the West Bank because then it has to give the Pals citizenship. To quote you Moxie, get with the programme and stop believing the hasbara!
Roadside bomb kills five border officers in western Iraq (AP)
from the article: Want to delegitimize Israel? Be careful who you mess with