They are letting in several thousands Arab laborers on humanitarian grounds due to US and EU pressure. At least that's how Israeli english language papers characterize the rationale.
Israel, sooner or later, will have to unilaterally withdraw from the West Bank and set new borders. However, that will neither stop the attacks nor the scorn of the Europeans and others who'd rather that Israel disappear as it impedes commerce with the Islamic/Islamist world which needs to be engaged (bought off). Israel will be assaulted in diplomatic arena for not withdrawing to pre-1967 borders. Once Israel is pressured to withdraw to those borders, it would be then pressured to let in Arab "refugees" conserved in that state since the 1948 War. If they cave in (and they will eventually) there will be a bloodbath in short order and the world will once again shed a few tears.
So the point is that no matter what Israel does the validity given to the Islamist perspective by the post-modern West will lead to the destruction of Israel as a state of the Jews. Unfortunately, we don't live in a rational world, not anymore at least.