Agreeing to their "right of return" and dissolving of Israel. Without it pals won't agree to any deal. Another words, the Palestinians want 2 Palestinian states. Only radicals like Gideon Levy, Amira Hass, Jeff Halper want that.
Aden hotel used by Yemen goverment hit by grenade (Reuters)
from the article: Aluf Benn / Who will blink first as peace talks stakes pile ever higher?