The real problem is that most politicians in Washington believe Netanyahu no longer has control of what happens in Israel, as his hands are tied by his allies of the fart right wing. Many politicians, no matter whether they're Republicans or Democrats, believe that it's better to wait till Bibi and Lieberman are ousted of power to take action. The second problem is that more and more people in US diplomatic circles believe that the Israeli-Palestinian conflict will never be solved and that Israel is doomed never to have peace. Sop they basically think the USA should do as little as possible in order not to put itself at risk.
Aden hotel used by Yemen goverment hit by grenade (Reuters)