Israel did not bomb Iran last year. Why should it happen this year?
Because it did not happen last year. The Iranians are proceeding apace with their nuclear program. The Americans are determined to stop them. Sanctions are biting, but the diplomatic process produced nothing visible in 2012. Knowledgeable observers believe there is no "zone of possible agreement." Both the United States and Iran may believe that they have viable alternatives to a negotiated agreement.