Could it be they have every reason not to trust him because:
1) He has sent U.S. generals to train and build a Palestinian army, which may very well turn their weapons against Israeli soldiers... and civilians;
2) When begging the American Jewish votes to get him the presidency, he stated unequivocally that Jerusalem would remain the undivided capital of the Jewish state, yet almost from the time he stepped into the WH he demands that East Jerusalem be the capital of a new Palestinian state.
3) He pledged to Saudi Arabia on June 3, 2009, that he would force Israel to withdraw from East Jerusalem and the entire West Bank by 2012
The list goes on and on . The Israelis were not born yesterday. They could have been fooled once by this silver-tongued lunatic but that's not likely to happen again. Obama has shown time and time again to those with eagle-eye perception that he is an anti-semite, while performing better than the best of the Oscar winners as being otherwise.