Once again, anonymous Israeli officials are telling local reporters that they're really, really ready to attack Iran's nuclear facilities, and they mean it this time. And once again, the top U.S. military officer is saying what a terrible idea that would be.

"I may not know about all of [Israel's] capabilities," Gen. Martin Dempsey, the chairman of the Joint Chiefs of Staff, told reporters last week. "But I think that it's a fair characterization to say that they could delay but not destroy Iran's nuclear capabilities." Left unsaid: in a few years, the U.S. and Israel would be back to the same standoff with Iran – except this time, it might do so amidst a proxy terrorist war to avenge the Iranians.

Nor does Dempsey think Iran is the kind of threat that requires imminent bombing, as he said on Sunday. "We compare intelligence, we discuss regional implications, and we've admitted to each other that our clocks are turning at different rates," Dempsey stated – softening the blow by adding, "We have to understand the Israelis; they live with a constant suspicion with which we do not have to deal."

Dempsey's comments would be unremarkable, even banal, if they had come at any other time. His boss, Defense Secretary Leon Panetta, pointedly told Israel in March that an American strike on Iran would be more effective than an Israeli one. Earlier, his Air Force colleague, the just-retired Gen. Norton Schwartz, questioned the strategic wisdom of bombing Iran, as well.

But it appears that Israel is moving toward a consensus that it has to strike Iran – now. And Israeli leaders are working hard to convince a reluctant and suspicious Obama administration to agree.

To be sure, media predictions of an imminent Israeli attack on Iran are nothing new. But this time, Israel's number-two diplomat, Danny Ayalon, wants President Obama to declare that efforts to negotiate an end to Iran's nuclear program have failed, which would be a prelude to an attack. The Israeli press is filled with alternatively panicked and solemn quotes from anonymous officials about the need to strike now. On Monday, Shaul Mofaz, Netanyahu's chief political opponent, asked the premier to provide the planning behind Netanyahu's "intention to lead Israel to war."

Meanwhile, Shimon Peres, Israel's president and the last remaining statesman of its founding generation, declared that a war with Iran would be folly; Netanyahu's aides attacked Peres as out of line. Writing in Foreign Policy magazine, Brandeis University professor concluded, "this weekend ended the Israeli debate on attacking Iran."

Wargames have demonstrated the likelihood of terrorist retaliation after a strike on Iran, as well as the probability that Israel won't be able to actually destroy the nuclear program justifying the war. Yet one of Israel's former intelligence chiefs argued in the Washington Post that among the only ways to stop Netanyahu from bombing was for Obama to say that he's really, really serious about attacking Iran himself... sometime down the road. A Times of Israel story breathlessly reported last week that Obama plans to secretly tell Netanyahu that he's going to war in June 2013.

Behind the scenes, U.S. officials laughed at that report. Obama isn't going to say anything of the sort. Not only does America not want to launch a fourth war against a Muslim country in a decade, but to pull up stakes on diplomacy would unravel the international sanctions coalition that the Obama team prides itself on building to keep pressure on Iran. The world would see Israel and the U.S. as the aggressors, instead of Iran. Chances are the price of oil would rise, which would not only be an economic drain, but would create massive pressure on the rest of the world to demand a U.S.-Israeli war end quickly – possibly, given the difficulty of attacking all Iranian nuclear sites, before completing the mission.

Dempsey is representative of the emerging U.S. military position: distrustful of Iran; wary of getting sucked into a war with the Iranians; and impatient with the idea that they have no way of dealing with the Iranians short of yet another war. And comments like his are what motivated Peres to speak out against the war – because he, and the rest of Netanyahu's political opposition, fear that one of the many casualties of a war with Iran could be the U.S.-Israeli relationship.