Fears that Israeli Prime Minister Binyamin Netanyahu, a right-wing hawk who has vowed to eliminate what hard-liners view as an existential Iranian threat to the Jewish state, could order a pre-emptive strike, have been emblazoned in headlines run by the liberal daily Haaretz in recent days.
"Netanyahu's messianism could launch attack on Iran," said one.
"Netanyahu must be stopped from attacking Iran," declared another.
Fifty-five U.S.-made bunker-busters, designated GBU-28 Hard Target Penetrators, were secretly delivered to Israel in 2009.
But despite his determination to defang Iran, Netanyahu hasn't launched an attack on Iran, even though he had the weapons needed to blast underground nuclear facilities.
However, concerns he could unleash them remain. For one thing, Netanyahu and Defense Minister Ehud Barak, himself a former prime minister and chief of staff, have in recent months carried out command changes on an unprecedented scale in Israel's military and intelligence arms.
Meir Dagan, director of Israel's foreign intelligence service until he stepped down in January, said commanders who opposed any attack on Iran because of the regional firestorm it would detonate have been dismissed.
Of the 18 living former chiefs of Israel's security establishment, eight have made known their opposition to Netanyahu's strategic thinking.
Another four "have made their alarm publicly clear though they aren't aggressively campaigning right now," one observer said.
These include Yuval Diskin, until recently director of the General Security Service, and Lt. Gen. Gabi Ashkenazi, edged out as chief of the general staff earlier this year.
Six of the others retired years ago and are keeping their thoughts to themselves, even though Netanyahu's reported enthusiasm for hitting Iran is becoming a public issue.
The other two, Barak and another ex-chief of staff, Moshe Yaalon, are serving in Netanyahu's coalition Cabinet. Yaalon is strategic affairs minister.
Dagan, a hard-charging former army general with a record of ruthlessness against Israel's enemies, has publicly declared that attacking Iran "is the stupidest thing I've ever heard."
He said Netanyahu and Barak were intent on plunging Israel into "a dangerous military adventure in Iran" that was certain to trigger a regional war that would ultimately threaten Israel's existence.
Dagan told one interviewer: "I decided to speak because when I was in office, Diskin, Ashkenazi and I could block any dangerous adventure. Now I'm afraid there's no one to stop Bibi (Netanyahu) and Barak."
"Netanyahu is completely serious in his desire. And in his preparations to circumvent the warnings of the entire defense establishment in order to implement this desire, which many of those in his inner circle have defined as messianic: to attack Iran before winter," one Haaretz commentary observed.
Israel had been pressing Washington for GBU-28s since 2005 but the Americans worried the technology would find its way to China, which Israel was selling military systems.
U.S. President George W. Bush eventually sanctioned the enterprise and Obama gave final approval when he took office. Both presidents opposed any unilateral Israeli strike against Iran.
At a Nov. 18, 2009, meeting between U.S. and Israeli military chiefs, a leaked U.S. diplomatic cable stated, "both sides … discussed the upcoming delivery of GBU-28 bunker-busting bombs to Israel, noting that the transfer should be handled quietly to avoid any allegations the USG (U.S. government) is helping Israel prepare for a strike against Iran."
It was probably not a coincidence that a week later Netanyahu imposed a 10-month settlements freeze in the West Bank at Obama's request in bid to galvanize the moribund peace process.
So why secretly transfer GBU-28s to Israel and then give the game away?
Some observers say Washington wanted to "hug Israel close" and make it feel secure. Others suspect leaking the transfer would give the Iranians pause knowing Israel could blast their nuclear sites.
Another explanation is that Obama was simply establishing his pro-Israel credentials in advance of a tough 2012 presidential campaign.
But what doesn't appear to be in doubt is that while U.S.-Israeli diplomatic relations are distinctly strained right now, military cooperation has been stepped up -- possibly to keep an eye on the Israelis.