When will Israel learn?

In an article in the New York Jewish Week, Israeli lawmakers recently visited Washington to urge the US to take steps to stop Iran from going nuclear, stating that if they didn't, then Israel would be forced to act as a last resort...

We told members of Congress that we had one Holocaust and that was enough - Tommy Lapid

Two quick observations:

1) Why should the US, or anyone else for that matter, act against Iran (and suffer the impending consequences of such an action) if they know that at the end of the day, Israel will do the job for them (and to put icing on the cake, the US would also be able to blame Israel for taking such strong measures and win points in the eyes of the Arab world and international community).

2) If Israel truly feels that a nuclear Iran poses an existential threat to the continued existence of Israel, and presents the possibility of a 2nd Holocaust, then why in the world is Israel wasting its time begging the nations of the world to fight its own fight. Is our memory truly so short that we have forgotten that during the 1st Holocaust, the US, along with just about every other country in the world sold the Jews down the river... The only difference today is that the Jewish People now have the means, through the State of Israel and the IDF to defend itself and not rely on others...

When will we learn...?

Israel
Zionism
Judaism