Former Prime Minister Ehud Barak Wednesday urged the United States to present Iranian leaders with a clear choice: abandon your nuclear aspirations "or else.""The Pentagon and the forces of America under the backing and probable directive of the [US] president [could] create an extremely effective means to destroy the Iranian nuclear military program over a fraction of one night," the former Israeli leader told CNBC.Barak added that it was preferable to see a peaceful end to Iran's nuclear threat.Ever since the framework of a deal between Iran and the US, along with world powers Russia, China, France, the UK and Germany, there have been conflicting accounts as to the exact nature of the agreement and what it means for chances of reaching a final deal."There is no agreement, basically," said Barak, arguing that President Barack Obama and his administration have painted themselves into a corner by committing themselves "all around the world and back home to pass this agreement." Despite the former prime minister's criticism of the Obama administration's handling of the negotiations, Barak says he still feels confident in America's commitment to Israel's security."The support of the administration to Israel in security, the cooperation and intelligence is unprecedented. I don't question for a moment the commitment of President Obama and everyone in that administration for the security of Israel."