He can't defeat the USA, EU, UN and the rest, who all support the Obama line. If he tries, he's looking at serious repercussions ref US diplomatic cover, finance, upgrade of EU ties, progress of the Goldstone report etc. He will not voluntarily relinquish personal power but is not strong enough to stand up to Lieberman, Yishai and the other extremist zealots on the right. Tzipi and Kadima offer him the only way out of the maze. It will be interesting to see how he goes about it, as it would take not just duplicity, which he has in abundance, but also wisdom and courage. Which I suspect are in rather short supply.
Russia vetoes UN resolution on MH17 special tribunal (Reuters)
from the article: Israel's Titanic moment: Does Obama want Bibi's head?