If Netanyahu negotiates in good faith, a unilateral declaration may not be necessary. The world will see. But if it is necessary, it would not be the first instance of a unilateral declaration. It seems that Israel did something similar and got recognized first by an ornery old man in the US.
Israel to cut VAT to 17%, corporate tax rate to 25%., says Netanyahu (Reuters)
from the article: Abbas: I don't want to declare unilateral statehood