Israel lacks the military infrastructure and resources for sustained campaign against Iran it would need to be successful
Israel also faces limits on its military capabilities. Strong as Israeli forces are, they lack the scale, range and other capabilities to carry out the kind of massive strike the U.S. could launch. Israel does not have the density and quality of intelligence assets necessary to reliably assess the damage done to a wide range of small and disperse targets and to detect new Iranian efforts. Israel has enough strike-attack aircraft and fighters in inventory to carry out a series of restrikes if Iran persisted in rebuilding, but it could not refuel a large-enough force, or provide enough intelligence and electronic warfare capabilities, to keep striking Iran at anything like the necessary scale. Moreover, Israel does not have enough forces to carry out a series of restrikes if Iran persisted in creating and rebuilding new facilities, and Arab states could not repeatedly standby and let Israel penetrate their air space. Israel might also have to deal with a Russia that would be far more willing to sell Iran advanced fighters and surface-to-air missiles if Israel attacked the Russian-built reactor at Bushehr. These problems are why a number of senior Israeli intelligence experts and military officers feel that Israel should not strike Iran, although few would recommend that Israel avoid using the threat of such strikes to help U.S. and other diplomatic efforts to persuade Iran to halt. For example, retired Brigadier General Shlomo Brom advocates, like a number of other Israeli experts, reliance on deterrence and Israel's steadily improving missile defenses.
Western intelligence experts believe that Iran's nuclear facilities are so deep underground that it would be difficult for Israel to wipe them out, or even significantly damage them, with a quick airstrike. In addition, depending on the flight route, Israeli aircraft would have to violate Jordanian, Syrian, Iraqi, or Saudi airspaces to strike Iranian targets.