US Defense Secretary Leon Panetta called Iran “a very grave threat to all of us” and said any Iranian disruption of the free flow of commerce through the Arabian Gulf is a “red line” for the US. He underscored President Barack Obama's determination to stop Iran from acquiring nuclear weapons. He also urged Israel to get back to the “damn” negotiating table with Palestinians and take steps to address what he described as Israel's growing isolation in the Middle East. In a speech at a Brookings Institution forum Friday, Panetta said that “no greater threat exists to the security and prosperity of the Middle East than a nuclear-armed Iran,” adding that Obama has not ruled out using military force to stop Iran from going nuclear. In a question-and-answer session with his audience after his speech, Panetta laid out in detail his thinking on the arguments against an Israeli or US military attack on Iran's nuclear facilities. He said such an attack would “at best” delay Iran's nuclear program by one or two years. Among the unintended consequences, he said, would be an increase in regional support for Iran and the likelihood of Iranian retaliation against US forces and bases in the Middle East. It also would have harmful economic consequences and could lead to military escalation, he said. “We have to be careful about the unintended consequences” of an Israeli or US attack, he said. Panetta urged Israel to “lean forward” to achieve peace with the Palestinians. “For example, Israel can reach out and mend fences with those who share an interest in regional stability,” he said. “Rather than undermining the Palestinian Authority, it is in Israel's interests to strengthen it by ... continuing to transfer Palestinian tax revenues and pursuing other avenues of cooperation,” he said. He said Israel needed to take risks, including by breathing new life into moribund peace talks with Palestinians. When asked by a moderator what steps Israel needed to take to pursue peace, Panetta said: “Just get to the damn table.” “The problem right now is we can't get ‘em to the damn table, to at least sit down and begin to discuss their differences,” Panetta said.