Major Israel Lobby organization AIPAC was leading the campaign against the Iran nuclear deal for years, and is now struggling to revise the appropriate confines of debate on the matter in the lead-up to President Trump decertifying the deal to try to kill it.
AIPAC insists that they take no specific position on whether or not Trump ought to decertify the deal. They are, however, heavily lobbying the administration and US Congress on a new round of sanctions which would amount to a breach of the deal.
Trump's decertification has become controversial because it looks almost certain to fail at forcing renegotiation. AIPAC appears to be determined to avoid any specific blame on that by structuring its hostility toward the deal as separate from the decertification issue.
Yet decertification is the mechanism through which Trump believes he can most easily kill the deal, which is what AIPAC's been insisting on from the start. In trying to be ambiguous on how the US should kill the deal, as they are still pushing for the deal to be killed, AIPAC is pushing the US down a reckless path while simultaneously preparing to dodge blame when it inevitably goes wrong.