A scenario you seldom hear. But if you think about it not very far fetched.
Israel has been a major pain to the USA since 1947. A very expensive pet that has proven to be a nuisance.
Now how to get rid of this pest in a manner that will seen as supporting them.
How about back Iran into a corner so that to show their autonomy Iran has to develop a nuclear program? Now push them through sanctions that they will initiate active hostilities. Most likely directed towards the closest US allie, Israel.
Blam--Israel is knocked off the map.
Washington sends Tehran a nasty telegram stating that Iran has been very bad and it they do not stop destroying neighboring countries, the sanctions will be increased. Tehran telegraphs back, "oops sorry about that, but Israel really got us angry." Washington replies back "Well don't let it happen again" and in a year normal trade and diplomatic relations are resotred between Washington and Tehran.
The USA is finaly rid of Israel and still looks good.
I personaly doubt that would happen. But, then again I've seen stranger things happen.
Although this has been grossly paraphrased by me, it is not as far fetched as it sounds.
I doubt if any of us have any inner knoledge as to what will happen if Iran continues with it's Nuke program