The International Atomic Energy Agency (IAEA) released its most recent report on Iran's nuclear activities, indicating that the Islamic Republic may have produced enough low-enriched uranium for its first nuclear weapon (if further enriched), on February 19. Meanwhile, Israeli Prime Minister-designate Binyamin Netanyahu is putting together a right-leaning government that, in his own words, would consider an Iranian nuclear weapon as "the gravest threat to [Israel's] existence since the war of independence." To complicate matters, Russia is considering the sale of the advanced S-300 air defense system to Iran, which is considered a "game changing" move that could affect Israel's calculus about whether, and when, to launch a preventive strike against Iran's nuclear infrastructure. This confluence of events - and the prospective transfer of the S-300 in particular - underscores the need for the United States to consider actions that could buy additional time to enable diplomacy to work. Reports of a possible Russian transfer of the S-300 to Iran are cloaked in uncertainty, with questions remaining as to which version is even being discussed. The S-300PMU-2 is a highly advanced, extremely capable air defense system known in the West as the SA-20. It is a highly mobile system, capable of intercepting low-altitude cruise missiles, ballistic missiles and high-altitude bombers. It can engage targets from altitudes as low as about 9 meters up to about 27,400 meters, and from a range of about 4.8 km. out to some 150 km. As a result, former commander of US Air Force Air Combat Command, Gen. (Ret.) Richard Hawley, said last August, "For non-stealth aircraft, the SA-20 represents a virtual no-fly zone." By contrast, the S-300V is a less capable system known in the West as the SA-12. The S-300V, in tandem with the Tor-M1 (SA-15) air defense system, are key elements of Moscow's air defense network, and it is possible that the S-300V is being considered for sale to Iran because it would integrate extremely well with the version of the Tor-M1 already deployed there. When pressed, Moscow denies any intention of selling the S-300PMU-2 to Iran, deftly avoiding discussion of the S-300V. In an attempt to influence the international environment and demoralize its enemies, Teheran is encouraging rumors that it is set to receive the S-300PMU-2, thus furthering the confusion. Teheran's tactics may be having an effect. Israel currently believes that its F-15I and F-16I aircraft maintain a viable strike option against Iranian nuclear targets. As long as this remains the case, Israel may remain receptive to US requests to give diplomacy more time. Increasingly clear, however, is that Israel regards the S-300 (in any configuration) as closing an important window of opportunity; Iran's acquisition of the S-300 would render Israel's current strike options dramatically more difficult, and could force Israel to considerably move forward any strike timetable. Should diplomacy fail, the United States can mount a powerful strike, regardless of the state of Iran's air defenses; Israel, operating at extreme range with the F-15I and F-16I, cannot. The F-22 fighter, however, might represent a trump card that could dissuade Russia from transferring the new air defense systems or that could preserve Israeli options should Russia go through with the sale. One possible option would be to use the proposed forward deployment of the F-22 to the region, or its transfer to Israel, as a means of slowing this timeline so additional international pressure can be brought to bear on Iran. There is little doubt that the F-22 can neutralize the S-300. As US Air Force Association President Lt. Gen. (Ret.) Mike Dunn stated last December, "Only the F-22 can survive in airspace defended by increasingly capable surface-to-air missiles" such as the S-300. Accordingly, the United States could deploy the F-22 to the region - for example, to bases in friendly Persian Gulf Arab states. Although the F-15s and F-16s already deployed to the region are more than capable for the current counterinsurgency fights in Iraq and Afghanistan, they would not be able to threaten Iran's nuclear infrastructure were the Islamic Republic to be armed with the S-300. As Ambassador Nancy Soderberg pointed out recently (at the release of The Washington Institute's Presidential Task Force report, "Preventing a Cascade of Instability: US Engagement to Check Iranian Nuclear Progress"), the United States "ha[s] lost the ability to scare" its adversaries in the region. Forward deployment of the F-22 could restore the credibility of the military option by indicating that it remains alive, and might even cause the Russians to reconsider the sale of S-300s to Iran. Alternatively, but more problematic, is the export of the F-22 to Israel to deal with the S-300 threat. Israel has long wanted to add the advanced fighter to its arsenal, but the F-22's export to any nation has been banned for over a decade as a result of the Obey amendment, which states that "None of the funds in this act may be used to approve or license the sale of the F-22A advanced tactical fighter to any foreign government." This amendment has been included in every defense appropriations act since 1998 in order to preserve the US commercial edge and technological superiority. These concerns could be overcome by advanced anti-tamper measures and strict export controls. And while Congressman Obey stated in 2006 that "Times may have changed, but I don't know that we are yet at the point that would justify removing these limitations," it may well be that in light of the Iranian nuclear threat and the possible introduction of the S-300 to the Iranian arsenal, the time may be ripe to rescind the restrictions and consider export of the F-22 to Israel. Repeal of the Obey amendment (which would require congressional action) would not automatically authorize an arms sale to the Israel Air Force, but would allow the export to be decided on its merits. The Israelis are concerned that the transfer of S-300s to Iran would foreclose their strike option. This could prompt an attack on Iranian nuclear facilities before diplomacy had run its course. By opening the door to the transfer of the F-22, Washington might convince Israel to postpone such an attack, providing US and international diplomatic efforts more time to succeed. Such a move could reassure Israeli decision-makers in much the same way that the deployment of Patriot missile batteries and Scud-hunting missions helped keep Israel out of the 1991 Gulf War with Iraq. Today, the F-22 might play a similar role in reassuring a US friend in the region. Military deployments and arms transfers have long been used by the United States to reassure nervous allies and to forestall undesirable actions. In keeping with this tradition, the United States should consider the forward deployment of the F-22 as a means of signaling its resolve on the Iranian nuclear issue. Washington should also consider rescinding the Obey amendment restrictions on F-22 export to pave the way for its eventual transfer. This action could buy policy-makers much-needed breathing room, allowing nuclear diplomacy with Iran time to run its course and, hopefully, to succeed. Thomas D. Crimmins is visiting National Defense Fellow in the Military and Security Studies Program at The Washington Institute for Near East Policy. Reprinted with permission of The Washington Institute for Near East Policy .