"Don't do it." That is the message American officials, from President Obama on down, are delivering to their Israeli counterparts in the hope of dissuading the Jewish state from taking a fateful step: attacking Iran to prevent the mullahs' imminent acquisition of nuclear weapons.
This week, the nation's top military officer, Chairman of the Joint Chiefs of Staff Martin E. Dempsey, will visit Israel to convey the same message in person. If recent reports of other U.S. demarches are any guide, the general will deliver an insistent warning that Israel must give sanctions more time to work and refrain from acting unilaterally.
Such warnings have become shriller as evidence accumulates that Israel is getting ready to move beyond what is widely believed to be a series of successful - but insufficient - covert actions against the Iranian nuclear program, missile forces and associated personnel.
Some U.S. officials reportedly think the Israelis are just posturing. As one put it, they are playing out a "hold me back" gambit - perhaps hoping the Americans will do the job themselves or at least hoping to be rewarded for their restraint.
Others point, however, to evidence that the Israelis are concealing key military movements from our intelligence assets as an indicator that they are going for it and want to keep us from interfering. At a minimum, Jerusalem would have to worry that an American administration that is holding secret negotiations with Tehran in Turkey at the level of Deputy Secretary of State William J. Burns would seek to curry favor with the mullahs by compromising any information it obtains about Israel's intentions.
At the end of the day, the fundamental difference between the United States and Israel is that the Israelis have laid down "red lines" with respect to the Iranian nuclear enterprise. One of them was crossed two weeks ago when the Iranians announced that they had started enriching uranium in a hardened and heavily defended underground facility near the city of Qom. Even the International Atomic Energy Agency - an organization that under its previous management incessantly obscured the true weapons purpose and steady progress of the Iranian nuclear program - views this step as ominous.
To be sure, the United States says it has red lines, too. It was just last week that Secretary of Defense Leon E. Panetta pronounced two: Iran would not be allowed either to acquire nuclear arms or to close the world's energy pipeline that flows through the entrance to the Persian Gulf, the Strait of Hormuz.
The difference between the American and Israeli red lines, of course, is that the Israelis actually may take seriously the breaching of theirs. Presumably, that would be because the government of Israel has drawn them so as to define existential threats to the state, not simply as a matter of rhetorical posturing intended mostly for domestic political consumption.
By contrast, we know that at least some Obama administration officials are persuaded that the United States can live with a nuclear Iran. They are said to be working up plans to contain, or at least accommodate themselves to, such a prospect.
It is less clear whether Team Obama actually thinks it can tolerate the mullahs' closure of the strait. After all, the oil and natural gas that flow through it from much of the Gulf's littoral states would be severely affected. The effect would be dire for energy prices, U.S. allies and the world economy.
So far, though, in what may be seen from Tehran - whether rightly or wrongly - as submission to the new, Iranian-dictated order of things, we have chosen to remove all carrier battle groups from the Gulf. We also have yet to challenge Iranian assertions that our capital ships will be attacked if they try to return without Tehran's permission.
Worse yet, even if President Obama actually wanted to enforce his administration's red lines, he has further compromised America's ability to do so with his wholesale abandonment of Iraq, draconian defense budget cuts and the emasculated national security strategy he claims is all we can afford.
Thus, the Israelis could reasonably view the United States as less than serious about the threats posed by Iran and as wholly unreliable when it comes to keeping them from metastasizing further. Under such circumstances, if the Jewish state feels it has no choice but to be deadly serious with respect to its red lines, its leaders must be expected to act as Iran violates them.
The likelihood for such action can only have grown as a result of the contempt with which Mr. Obama has treated Israel, our most important regional ally. Dissing Prime Minister Benjamin Netanyahu is one thing. Allowing our own red lines to be flouted with impunity signals that Israel is on its own and must proceed accordingly.
If we are going to stop the nightmare of a messianic regime armed with nuclear missiles, somebody had better do it soon - and with something more effective than sanctions. America should take the lead. However, if the Obama administration won't, it should get out of the Israelis' way.
Frank J. Gaffney Jr. is president of the Center for Security Policy (SecureFreedom.org), a columnist for The Washington Times and host of Secure Freedom Radio, heard in Washington weeknights at 9 p.m. on 1260 AM.