Israel has been working with Fatah. The PLO with the aid of the US and Israel has trained 30,000 security officers and improved governance. But, in 2006 Hamas was elected because the PLO was wasn't working for the voters. Israel should want to deal with the PLO and negotiate in good faith otherwise more aggressive people will take over, With the turmoil in the area, it appears groups uncooperative with Israel will take over more countries.
ISIS kills 22 in Yemen's Sanaa, Aden; targets both gov't and Houthi rebels (Reuters)
from the article: Obama: All options remain on the table to prevent a nuclear Iran