The strategic relationship between Israel and the United States could collapse amid their dispute over Iran.

In three simulations conducted in Israel and the United States, relations between the two countries declined rapidly amid a dispute over a response to Iran’s nuclear weapons program. The simulations envisioned a diplomatic crisis as Washington sought to stop Israel from attacking Iran.

“The United States was unwilling to use military force or support Israeli military action even after other measures failed,” a report on the three simulations said. “U.S.-Israeli relations deteriorated dramatically.”

The report by the Washington Institute, titled “Serious Play: War Games Explore Options on Iran,” reviewed the war games conducted by three leading Western strategic institutes.

In December 2009, Brookings Institution, Harvard University, and Israel’s Institute for National Security Studies conducted separate simulations to analyze Iranian nuclear scenarios, with leading strategists playing the leadership of Iran, Israel and the United States.

“And three recent war games focused on the Iranian nuclear weapons issue suggest that the prospects for halting the regime’s progress toward nuclear weapons are not good,” the report, authored by defense fellow Jeffrey White, said. “The results, unfortunately, were uniformly negative.” Both governments and militaries employ simulations to help form decisions and tactics. Usually, outside consultants draft the initial scenario and monitor the responses to ensure realism.

White, a former Defense Department analyst, reviewed all three simulations. He said all three war games, with a scenario that envisioned the emergence of Iranian nuclear weapons, ended with a bolstered Teheran and tattered Israeli-U.S. relations.

The Harvard simulation, organized by the Belfer Center for Science and International Affairs, concluded that President Barack Obama would fail to garner international support for sanctions against Iran. At the same time, Jerusalem and Washington would grow apart amid disagreement over a nuclear Iran.

“The U.S.-Israeli relationship deteriorated dramatically during the game, leading to a deep diplomatic crisis,” the report said. “Indeed, most observers would probably characterize the outcome as a win for Iran and a defeat for the United States and Israel.”

The Brookings simulation also ended with U.S. anger toward Israel as Washington attempted to avoid conflict with Iran. In this war game, Israel actually attacked Iran’s nuclear facilities.

“The United States was unhappy with Israel over the attack.” the report said. “The United States tried to talk tough with Iran but also sought direct negotiations.”

In Tel Aviv, INSS envisioned an indecisive Israel and the United States amid Iran’s advancement toward nuclear weapons. At the end of the simulation, Iran also emerged undeterred by either Jerusalem or Washington. “Israel and the United States lacked clear goals and strategies for dealing with Iran’s program,” the report said. “Israel was perceived as being unhelpful to the United States.”

The war games suggested that Israel’s military option against Iran would mark a leading challenge to U.S. strategy in the Middle East. The report said the simulations pointed to disputing assessments regarding the threat from Iran’s nuclear program.

“The United States eschewed military action to avoid the attendant risks, while Israel was more willing to take the risks to avoid, or at least postpone, the nuclear threat,” the report said. “Game play suggests that an eventual U.S.-Israeli crisis is likely.”

White urged the Obama administration to revise its strategy and tactics toward a determined Iran. He cited a U.S. option for regime change in Teheran as well as plans for military action against Iran.

“The United States must plan for military action, either by itself, with others, or in the wake of unilateral Israeli strikes,” the report said.

“Both the military and the public should be prepared for the consequences of these scenarios. These preparations must be carried out with the full understanding that the military option is practicable — and, at the end of the day, may well be the required course of action.”

Another recommendation was that Israel prepare both the military and civilian sector for what White termed an “extended war on multiple fronts and deep within the homeland.” Such a war, he warned, could result in casualties and disruption of civilian life.

“Israel already appears to be moving in this direction, and that course seems wise given the outcome of the war games,” White said. “Time is running out.”