Israel is seriously considering taking unilateral military action to stop Iran from acquiring nuclear weapons, according to a report by top US political figures and experts released Wednesday. The report also says Israel's time frame for action is growing shorter, not only because of Iranian advances, but because Teheran might soon acquire upgraded air defenses and disperse its nuclear program to additional locations. The report, "Preventing a Cascade of Instability," was put out by the Washington Institute for Near East Policy (WINEP). It also argues that international sanctions against Iran need to be intensified urgently for the engagement the Obama administration is planning with Teheran to be effective. An early draft of the report was endorsed by Dennis Ross before he withdrew upon joining the Obama administration, in which he is serving as a special adviser dealing with various countries in the region, including Iran. Senator Evan Bayh of the Senate Select Committee on Intelligence, and Congressman Gary Ackerman, chairman of the House Foreign Affairs subcommittee on the Middle East, were among the signatories. The bipartisan group also recommended increasing security guarantees and the supply of missile defenses and other protective measures to allies in the Middle East, both to reassure them of America's commitment to them and to dampen the perceived effectiveness, and hence appeal, of nuclear weapons for Iran. But the report, several of whose authors met with high-level Israeli officials to assess their perspective, notes that Israel is not interested in becoming part of an American nuclear umbrella, even as Gulf countries want more assurances on that front. "A declared US guarantee would clarify a situation of ambiguity that may already work to Israel's advantage," the report notes. Also, "many Israelis fear that a declared US guarantee could come at the price of circumscribing Israel's freedom of action in confronting existential dangers." "It's quite serious in acting on its own about a nuclear-armed Iran," former US ambassador to the United Nations Nancy Soderberg, one of the task force members who traveled to the region to research the report, said at a WINEP event held Wednesday on the report's release. She noted that the timetable for an Israeli attack might be "significantly" moved up if Jerusalem believed Russia was going to make good on its pledge to supply Iran with the S-300 surface-to-air missile system, which would greatly complicate any Israeli attack. If the delivery does occur, the report recommends more arms sales to Israel, such as more modern aircraft, so it can maintain its military edge. Later, she said that the aim of the report was to come up with strategies where neither the United States nor Israel was at the point of launching military action. "You've kind of lost the ballgame at that point," she said. To that end, the 10-page document urges more international sanctions and expanding financial pressure taken by the US Treasury, by creating similar programs at the US Commerce and State Departments. The study stresses the importance of having a united global front and pushes for intensified diplomacy with Russia to both make sanctions more effective and to persuade the Russians not to deliver the S-300 system. "Iran does not want to be isolated on the international stage: It is not North Korea. The broader the international consensus, the better. The repeated shows of unanimity by the UN Security Council seem to have impressed Iran more than the limited economic or security impact of the sanctions imposed thus far," the report states, in making the case for more sanctions. At the same time, it contends that aggressive engagement is needed because "another important goal is to show the Middle East and the world that the United States will go the extra mile to resolve the Iranian nuclear issue. Some circles in countries friendly to the United States now wonder - without reason - if Washington is as much an obstacle to resolving the nuclear impasse as is Teheran." Even if engagement, sanctions and other measures prove ineffective, the report warns against sanctioning a "fallback" policy where Iran is allowed to have some, even if limited, capacity to enrich uranium in its territory. "Iran's having a latent capability to quickly make nuclear weapons could lead to much the same risk of cascading instability as an Iran with an actual weapon," it reads, pointing to the risk for nuclear proliferation, Iranian regional hegemony and more. The report makes no mention of the presidential elections in Iran this June, which could see the more moderate Muhammad Khatami replace fiery current President Mahmoud Ahmadinejad. Some analysts have suggested that the Obama administration wait to either engage or press for further sanctions until after the campaign, so as not to increase the likelihood of Admadinejad winning. But the task force calls for immediate action, arguing that the president is less important than Iran's supreme leader, Ayatolla Ali Khamenei, in making decisions and that the top priority should be creating leverage heading into negotiations. An Iranian professor in the audience at Wednesday's WINEP conference, however, said that increasing pressure would increase extremism and Iranian hard-line leaders' sticking to the nuclear program. WINEP executive director Robert Satloff, who presided over the conference, responded that the report's recommendations also included many incentives for Iran should it cooperate with the United States. He also said Iran was already beginning to reap some of the rewards of influence just by having been successful in advancing its nuclear program, and that this report was intended to stanch that progress. "Even without testing a nuclear weapon or declaring the ability to do so, Iran's progress toward nuclear weapons capability is already having a substantial impact on the Middle East," it says. "Time is short if diplomatic engagement is to have a chance of success."