The International Herald Tribune is reporting that a large Israeli air exercise has taken place earlier this month, in what appeared to be a rehearsal for a potential bombing attack on Iran's nuclear facilities.
More than 100 Israeli F-16 and F-15 fighters participated in the maneuvers, which were carried out over the eastern Mediterranean and over Greece during the first week of June, American officials said. The exercise also included Israeli helicopters that could be used to rescue downed pilots. The helicopters and refueling tankers flew more than 900 miles, which is about the same distance between Israel and Iran's uranium enrichment plant at Natanz, American officials said.
[T]he scope of the Israeli exercise virtually guaranteed that it would be noticed by American and other foreign intelligence agencies. A senior Pentagon official who has been briefed on the exercise, and who spoke on condition of anonymity because of the political delicacy of the matter, said the exercise appeared to serve multiple purposes. One Israeli goal, the Pentagon official said, was to practice flight tactics, aerial refueling and all other details of a possible strike against Iran's nuclear installations and its long-range conventional missiles. A second, the official said, was to send a clear message to the United States and other countries that Israel was prepared to act militarily if diplomatic efforts to stop Iran from producing bomb-grade uranium continued to falter. "They wanted us to know, they wanted the Europeans to know, and they wanted the Iranians to know," the Pentagon official said. "There's a lot of signaling going on at different levels."
Iran has shown signs that it is taking the Israeli warnings seriously, by beefing up its air defenses in recent weeks, including increasing air patrols. In one instance, Iran scrambled F-4 jets to double-check an Iraqi civilian flight from Baghdad to Tehran. Iran is also taking steps to better defend its nuclear facilities. Two sets of advance Russian-made radar systems were recently delivered to Iran. The radar will enhance Iran's ability to detect planes flying at low altitude. Mike McConnell, the director of national intelligence, said in February that Iran was close to acquiring Russian-produced SA-20 surface-to-air missiles. American military officials said that the deployment of such systems would hamper Israel's attack planning, putting pressure on Israel to act before the missiles are fielded.
This isn't the first Israeli exercise of this type, but it may be the largest and most detailed. In the past, Iran has even reciprocated by conducting a similar type air exercise of its own.
Update: For analysis on Israeli strike options, view the following:
Iran - Israel's Strike Options by USAF Lt Col Rick Francona
Israeli and US Strikes on Iran: A Speculative Analysis by Anthony H. Cordesman
Osirak Relux? Assessing Israeli Capabilities to Destroy Iranian Nuclear Facilities by Whitney Raas and Austin Long