Abbas' PLO avoids meaningful negotiations by putting obstacles in front in the form of unreasonable conditions. Israel could do the same. For example, Jerusalem must remain undivided capital of Israel is one condition or that Israel must retain control of ALL Jewish communities over the imaginary green line or that the PLO must agree to be demilitarized. These are most likely are going to be in the final agreement anyway, so why not also make them preconditions? The PLO refuses to negotiate and this illustrates how they are THE obstacle to peace.
Palestinian youths throw stones at security forces in Shoafat, E. Jerusalem; none injured (Haaretz)
from the article: Netanyahu, Obama talk Mideast peace, Iran nuclear standoff