What the US can do is very limited. It can give Israel money and weapons and veto resolutions but it cannot break the will of the Palestinians for an independent Palestion state. The US has not been able to convince other countries not to recognize the Palestinians and the 1967 boarders. Obama, Romney and McCain refused to answer the question whether the US is willing to go to war if Iran attacks Israel.
Lieberman: Knesset panel should review attack on IDF soldier in Nabi Saleh (Haaretz)
from the article: Thanks, Mr. Romney, for explaining why Jews should vote Obama