In The Drums of August, David Rothkopf does a superb job in discussing the dangerous context of the Israel-Iran problem but in doing so also lays out the general context for the current situation in the Middle East and the challenges that arise with the old, established order decays or is upended and a new order has yet to be established. Our current budget problems have certainly provided plenty of fresh wind to the long-running debate about America's role in the world. Whether discussed in terms of "global policeman," "neocolonial great power," "global busybody," "guarantor of access to the global commons," or "that shining city upon a hill" the fact of the matter is that the U.S. has global interests in the economic realm and as an extension our values, primarily in terms of individual freedom and acknowledgement of 'unalienable rights' of Man endowed by our Creator. Like nature, politics abhors a vacuum. When a dominant power declines other powers compete for dominance in the space that is left vacant. As Rothkopf points out, the Great Powers of the 19th and 20th Centuries provided a framework for order in much of the world. The end of the Cold War, the current reluctance of the U.S. to remain engaged as the dominant global power, and the aspirations of others (China, Russia, Iran, etc.) have combined to create a new vacuum in which new contests are being waged. America might not want to shoulder the costs of foreign engagement but it will have to bear the burden of the consequences of that decision nonetheless.
As for Israel and Iran, I think Michael Ledeen has provided the best observation yet in his most recent post on the matter, The Israel/Iran War Game.
In short, we can surmise and guess and debate and suppose all we want but unless we're actually involved in the most private of discussions currently ongoing in both capitals (Jerusalem and Tehran), we just won't know until whatever happens, happens. Regardless, it is in our (America's) power to decide whether to be influential or not. Personally, I hope we make whatever investments are necessary to 'call the shots' rather than be at the mercy of others who will not have our best interests at heart.