WASHINGTON – Introducing a controversial bill last week long in the works, Senator Robert Menendez and a bipartisan group of 25 senators sent a clear message to US President Barack Obama: We don’t trust your administration to handle Iran on its own.The bill, called the Nuclear Weapon Free Iran Act of 2013, would trigger a new round of sanctions against the Islamic Republic should a six-month interim agreement, forged last month in Geneva, expire without a comprehensive deal ending their nuclear program.The Geneva deal agreed upon by Iran and the P5+1 powers – the US, United Kingdom, France, Russia, China and Germany – effectively halts Iran’s nuclear program in exchange for modest sanctions relief. But the deal includes a provision that was made available to Senate members well in advance of its signing: that “the US administration, acting consistent with the respective roles of the President and the Congress, will refrain from imposing new nuclear-related sanctions.” Opponents of the deal in Congress do not believe Treasury Secretary Jack Lew when he insists, repeatedly, that the core sanctions regime – passed by Congress itself or independently ordered by the president – will remain unaffected by the deal.Bill Kristol, editor of the conservative The Weekly Standard magazine, called the Geneva agreement “unfortunate” in an interview.“It’s a bad deal,” Kristol said.“It gives up the sanctions in a way that would be very hard to reverse, in return for no real dismantling or even setback of the Iranian nuclear program.”Nor do conservatives trust US Secretary of State John Kerry when he speaks of alliance management. Kerry says that China, Russia and the European Union will no longer believe the US is genuinely working toward a peaceful diplomatic solution to the Iranian nuclear crisis if it appears interested only in inflicting punishment; yet the US has already eroded the trust of other allies, namely Saudi Arabia, Qatar and Israel, opponents retort. It may be that the standard for these members of Congress, and the allies they speak of, is a form of Persian capitulation that will never realistically come to pass.One consistent line from the Iranians has been that they will never forgo their right to a civilian nuclear program.And to support diplomacy, a deal must be had; compromise must be made.Congress led the way on sanctioning Iran throughout 2010 and 2011. But if Kerry is correct, then Menendez’s new bill could risk fraying a coalition put together not by Congress, but by the Obama White House.“When the president says a major foreign policy priority would be torpedoed if it acted, it’s very hard for Congress to act,” said Patrick Clawson, director of research at the Washington Institute for Near East Policy.“I don’t think Democrats want to embarrass the president,” Clawson added, “and Republicans don’t want to give the president an opportunity to say that his strategy would have succeeded without Republican obstructionism.”And yet Menendez seems to believe his bill will not violate the Geneva agreement any more than has the designation of new companies as sanctions violators, as was done last week by the departments of State and Treasury. The Iranians have explicitly said otherwise. Iranian Foreign Minister Mohammad Javad Zarif has warned that passage of this bill would render the Geneva agreement “entirely dead.”No doubt, testing Iran’s threats and lighting fire under the deal are risks these senators are taking with eyes wide open.Kristol, a leading conservative voice calling for robust penalties against Iran, sees a “desperate desire” on the part of the Obama administration “to have a deal to avoid facing real choices” that compel Iran to end its nuclear program.The US should “make much clearer that we are willing to use force,” Kristol said, advocating tougher sanctions legislation.He noted that Iran pulled the plug on its nuclear program after the US invaded Iraq. “They [Iranians] were scared.”“We are hitting the fork in the road,” he added.