In an exclusive story to be published Monday on growing military cooperation between the two allies, U.S. and Israeli officials tell Newsweek that the GBU-28 Hard Target Penetrators—potentially useful in any future military strike against Iranian nuclear sites—were delivered to Israel in 2009, just several months after Obama took office.

The military sale was arranged behind the scenes as Obama’s demands for Israel to stop building settlements in disputed territories were fraying political relations between the two countries in public.

The Israelis first requested the bunker busters in 2005, only to be rebuffed by the Bush administration. At the time, the Pentagon had frozen almost all U.S.-Israeli joint defense projects out of concern that Israel was transferring advanced military technology to China.

In 2007, Bush informed Ehud Olmert, then prime minister, that he would order the bunker busters for delivery in 2009 or 2010. The Israelis wanted them in 2007. Obama finally released the weapons in 2009, according to officials familiar with the still-secret decision.

James Cartwright, the Marine Corps general who served until August as the vice chairman of the Joint Chiefs of Staff, told Newsweek the military chiefs had no objections to the sale. Rather, Cartwright said, there was a concern about “how the Iranians would perceive it,” and “how the Israelis might perceive it.” In other words, would the sale be seen as a green light for Israel to attack Iran’s secret nuclear sites one day?