A recent research project by the IAF has determined that in the summer of 1981 Israel did not have a clear picture of the impact a strike on Iraq's nuclear reactor would have, but chose to attack anyway. Prime minister Menachem Begin ordered the bombing, condemned by the world at the time, thus inaugurating what became known as the 'Begin Doctrine,' Israel's policy of launching a pre-emptive strike to prevent any of its enemies acquiring nuclear weapons. It is the Begin Doctrine which repeatedly has been invoked lately regarding Iran and Israel's response to its suspected efforts to produce nuclear weapons. The internal IAF research paper shows that the feasibility of a successful military operation need not be total in order for Israeli leaders to order such a strike. This appears to abate a recently published US army report that claims Israel has no viable military option against Iranian nukes. According to a senior Air Force officer who was privy to the IAF paper, the intelligence available at the time of the June 1981 strike on the Iraqi reactor at Osirak was only partial and it was unclear whether the planned air raid would be effective. "At the time, there was no firm information on either the extent of the damage that the strike could cause or whether it would have a fatal impact on the Iraqi nuclear program. The information he had was very partial, even to the extent of the physical damage we could do to the target and how much it would delay the Iraqi program," said the senior officer. But that was history and today it is Iran and its nuclear program that weighs heavy on their minds. The IAF officer said that Iran is increasingly fearful of attack. "But they are limited in their ability to create an effective air defense," he said. According to intelligence, Iran has beefed up its air defenses around various nuclear sites as a precaution against a possible pre-emptive strike by US or Israeli forces. The source described the present Iranian air defenses as 'good.' It is known that Iran has deployed Soviet-origin anti-aircraft systems around the 1000-megawatt Bushehr nuclear reactor. Iran's air defense contains Russian SA-2, SA-5, SA-6 as well as shoulder-launched SA-7 missiles, according to The Military Balance published by the Jaffee Center for Strategic Studies. They also have aged US-made Hawk missiles and have been seeking to purchase the sophisticated S-300P from Russia. One war game scenario played out by the IAF was an American attack on Iranian nuclear sites. In this case, it was believed the US would give Israel a prior warning of 'perhaps a day, nothing significant.' "There is no way the Iranians would believe that it was the Americans and [they] will seek to retaliate against Israel," a senior officer said. The officer declined to say whether there were key targets in Iran that, if destroyed, would seriously set back their nuclear program. "I will have to provide targets to the generals so that they can offer various options to the government,' the senior officer said. 'We have to be able to provide answers all of the time for potential targets." Ironically, the Israeli F-16s that bombed Osirak were actually built for the Iranians. Israel received them instead after the Islamic revolution toppled the shah and the US imposed an arms embargo on Teheran. Today, the IAF has a new generation of F-16s custom built for striking Iran.