A tourist who visited the Kirya in Tel Aviv this week could have been excused for mistaking the IDF Military Headquarters for an American army base. After all, it is not every week that the chairman of the Joint Chiefs of Staff visits Israel - certainly not mere days following a visit by two four-star generals. The week began with the arrival of Chief of Naval Operations Admiral Gary Roughead, who had come to meet his Israeli counterpart, Vice Admiral Eliezer Marom. Both took up their positions in late 2007, and they have already met three times - twice in the US, and now this time in Israel. This is the most, Roughead told The Jerusalem Post, that he has met with any other foreign Navy commander. In the middle of the week, Gen. William S. Wallace, commander of the US Army Training and Doctrine Command, landed in Tel Aviv. He was here as the guest of OC Ground Forces Command Maj.-Gen. Avi Mizrahi. In contrast to Roughead's visit, which was covered by the media, the IDF refused to provide details surrounding the purpose of Wallace's trip here. Wallace is responsible for a wide range of issues, including the recruiting, training and education of US Army troops. A recent op-ed he wrote for the East Valley Tribune read like a piece that could have been authored by an Israeli general protesting declining draft numbers. In Israel, he wrote, 25 percent of youth may be evading the draft, but in the US, only 28% of the 17-24-year-old population even qualifies to wear a military uniform. After Wallace and Roughead flew back home on Thursday, it was their boss's turn to arrive. Chairman of the Joint Chiefs of Staff Admiral Michael Mullen - as was reported exclusively in The Post this week - decided to cut short a scheduled tour of Europe to fly to Tel Aviv over the weekend for talks with his Israeli counterpart, IDF Chief of General Staff Lt.-Gen. Gabi Ashkenazi. This is significant. Until Mullen's previous visit to Israel in December, no joint chiefs chairman - the highest military position in the US - had been here in more than a decade. This week's visit is his second since taking up the post less than a year ago, and comes just weeks before Ashkenazi is scheduled to fly to Washington to meet with him there. This sequence of visits was explained by IDF Spokesman Brig.-Gen. Avi Benayahu as "routine trips dealing with many areas of cooperation." Fair enough. But they come just two weeks after it was reported that the Israel Air Force had conducted one of the largest aerial exercises in its history. The IAF allegedly flew 100 F-15 and F-16 fighter jets - supported by midair fuel tankers and rescue helicopters - 1,500 kilometers westward over the Mediterranean Sea. This just happens to equal the distance eastward from Israel to Iran's nuclear facilities. In addition, the meetings coincide with a recent escalation in Israeli rhetoric vis-Ã -vis Iran. Earlier this month, Deputy Prime Minister Shaul Mofaz said Israel would have no choice but to attack Iran. Other officials, too, such as Foreign Minister Tzipi Livni and Israeli ambassador to the US Sallai Meridor, have made similar, if less definitive, remarks. From an Israeli standpoint, the military option is certainly viable, though it rests on many variables, and is considered a "last resort." Israel would prefer not to have to fly 100 of its fighter jets across the world, but - as it demonstrated in the reported massive air display over Greece - it is prepared to do so. LONG-RANGE fighter-jet exercises are nothing new. As The Post reported on Sunday, the IDF has significantly increased its participation in overseas exercises in recent years - in the US, Canada, Spain, Greece and Italy. Flights by the IAF's International Squadron - responsible for midair refueling - have also dramatically increased. Maj.-Gen. Elazar Shkedy, who stepped down last month as commander of the IAF, was said to have jumped at every invitation from foreign militaries to fly his jets to their countries. With so little available air space in Israel, the IAF needs every opportunity to test its long-range capabilities, and the only way to so is by going abroad. This is not only in order to ensure that the planes meet their long-range requirements, but also to test different munitions. The reason these flights have not received much attention is because, in comparison to the reported exercise held over Greece earlier this month, they have been small in size. And though Israel did not confirm that it had held the major exercise over Greece, it was not disturbed by last Friday's New York Times report about it. "You don't fly 100 jets over the Mediterranean and expect no one will see it," explained one defense official. Roughead told The Post that he knew of the reported exercise, and that "there are many ways we [the US Navy] receive information." Greek defense officials confirmed the unusual aerial activity. It is also likely that ships belonging to NATO, Russia and Syria, which regularly frequent these waters, did not turn a blind eye to the jets with the stars of David on their wings. Though Israel has remained mum on the intent of the reported exercise, officials in the Pentagon speculated that it wanted the world to take notice - to see that it is serious about its military threat against Iran. This assessment makes sense, since Israel is becoming increasingly frustrated with the faltering diplomatic efforts to stop Iran's nuclear program. With oil prices rising, Iran stands to earn more than $100 billion from oil exports this year, up from about $75 billion in 2007, itself a record year. This increase in revenues is believed to be partially behind Iran's rejection of the new incentive package offered by the European Union, which included support for a civilian nuclear energy program and R&D. Another thing the reported exercise over Greece demonstrated was how dependent Israel would be on other countries, in the event of an attack on Iran. THIS IS why the meetings held at the Kirya this past week were so important. Though both sides deny they are coordinating operational plans to attack Iran, it is likely that feelers are being put out by Israel to see what type of support, if at all, it could expect to receive from the US in the event of an airstrike. As demonstrated by past coordination between the two countries - during the Yom Kippur War, for instance, when the US sent weaponry to the IDF, and surrounding Israel's September bombing of the Syrian nuclear reactor, for the Bush administration gave its consent - it is not likely that Israel would be able to strike Iran without first coordinating it with the US. This coordination could take the form of an unspoken understanding that allows the IAF to fly over Iraq, or perhaps even include permission to use American bases in the Gulf to refuel and rearm. Meanwhile, there are other challenges on the horizon that have to do with unknown variables. One such variable is that Teheran is believed to have purchased, but not yet received, the advanced Russian-made S-300 air defense missile system, capable of tracking dozens of targets and engaging over a dozen of them simultaneously at a range of hundreds of kilometers. Senior IDF officers have warned recently that this system cannot be allowed to reach the region. If it does, it would pose a major obstacle to an Israeli strike, and as a result, the IDF might be prompted to launch such an attack before the system is deployed in Iran. Another unknown variable is the domestic situation in Iran. Presidential elections are scheduled for mid-2009, shortly after John McCain or Barack Obama move into the Oval Office. According to a Newsweek report this week, current President Mahmoud Ahmadinejad stands a 50% chance of losing reelection, in light of growing inflation. Supreme Leader Ali Khamenei may decide not to support the incumbent president, and instead push for a conservative candidate who may be more open to EU incentives. Israel may be inclined to allow that process to play out, and therefore might hold off on an airstrike until after the Iranian elections. On the other hand, there is the question of what the US will do. According to a recent CBS report, Vice President Dick Cheney is in favor of attacking Iran, against the recommendations of Mullen and Defense Secretary Robert Gates. Still, one window of opportunity to do so that has been suggested is the period between the US presidential elections in November and the inauguration in January 2009. There is no guarantee, however, that Israel can wait that long.