From Foreign Policy, Mark Perry breaking the story:
[...] In particular, four senior diplomats and military intelligence officers say that the United States has concluded that Israel has recently been granted access to airbases on Iran’s northern border. To do what, exactly, is not clear. “The Israelis have bought an airfield,” a senior administration official told me in early February, “and the airfield is called Azerbaijan.”
Senior U.S. intelligence officials are increasingly concerned that Israel’s military expansion into Azerbaijan complicates U.S. efforts to dampen Israeli-Iranian tensions, according to the sources. Military planners, I was told, must now plan not only for a war scenario that includes the Persian Gulf — but one that could include the Caucasus. The burgeoning Israel-Azerbaijan relationship has also become a flashpoint in both countries’ relationship with Turkey, a regional heavyweight that fears the economic and political fallout of a war with Iran. Turkey’s most senior government officials have raised their concerns with their U.S. counterparts, as well as with the Azeris, the sources said.
The Israeli embassy in Washington, the Israel Defense Forces, and the Mossad were contacted for comment, as well as the Azeri embassy to the United States, but none was forthcoming.
Haaretz has a report pointing out problems with the supposition of Israel hitting Iran from Azerbaijan.
While this is an intriguing possibility, a cursory glance at a map hardly bears it out. A range of American military experts claim that Azeri airfields would be invaluable for Israel as it would solve some of the fuel/range issues of a 2000+km strike, they fail to address the problem of where the Israeli warplanes can fly to once they have refueled in Azerbaijan. There is no friendly route to fly back to Israel, except over Iranian or Turkish territory, hardly appealing alternatives once an attack has already been carried out and both countries will be on highest alert. Another weak point in that theory is that according to a “senior U.S. military intelligence officer” this would enable the Israeli air-force not to rely on its “pretty minimal” aerial refueling capabilities with which U.S. “military planners… are not impressed.”
This is simply nuts.