Last week, Secretary of Defense Leon Panetta did Iran a favor by publicly pouring cold water on the possibility of the United States using force to prevent Tehran from acquiring nuclear weapons. In doing so, the Pentagon chief removed whatever lingering doubts the ayatollahs may have had about America’s long-term intentions. This peace of mind will, no doubt, spur them to redouble their efforts to go nuclear. But in case they missed that message, the secretary doubled down on it yesterday. According to Reuters, Panetta told reporters (who had accompanied him on a trip to Halifax, Canada, where he will attend a security forum and meet with Israeli Defense Minister Ehud Barak), the same points he mentioned last week about the unintended consequences of an attack on Iran and how it would only delay their nuclear program. He added that such hostilities would also hurt the world economy.

While there are good reasons to be cautious about embarking on a military campaign against Iran, Panetta’s concerns are overblown. But more importantly, with this second statement in a week against an attack, Panetta’s priorities on the issue are becoming clear. At this point, he’s not so much trying to stop Iran from going nuclear as he is doing all he can to make sure Israel doesn’t attack them.

As for Panetta’s worries about the use of force, it’s true even a full-scale American bombing campaign on Iranian nuclear targets would not end the threat for all time. But the use of force would delay their nuclear project for years; if the U.S. military’s job was thorough, perhaps quite a long time. But however much time was bought, it would not be in vain. Because an Iranian nuclear presents a strategic challenge to the entire region as well as an existential threat to Israel, every day of peace purchased by such an offensive would be precious. In the meantime, a lot could happen to prevent further mischief, such as regime change in Tehran or the development of even better anti-missile defenses. Even a few years could make the difference between life and death for millions.

Panetta’s also right that another war in the Persian Gulf would have a big impact on the global economy. But what does he think the consequences of Iranian nukes would have on world finances? An Iranian nuclear bomb would give Iran outsized influence over the world’s biggest suppliers of oil and perhaps give them the ability to hold the world hostage. An Iranian nuclear umbrella over Iran’s terrorist proxies in Lebanon and Gaza would also make the region more dangerous and perhaps set in motion a chain of events that could do just as much damage to the financial world as an effort to prevent the ayatollahs from gaining nukes.

The United States has no easy choices when it comes to Iran. Russian and Chinese backing for Iran dooms efforts to create meaningful international sanctions. Military action would be costly and messy, as Panetta rightly insists, with unintended consequences that could be complicated.

But we also know that doing nothing — and it must be said that the Obama administration’s feckless diplomacy on the issue has turned out to be the moral equivalent of nothing — will be just as dangerous and costly. Whatever the United States’ intentions regarding Iran, it’s imperative for Panetta to stop sending signals to Tehran that demonstrate the administration’s unwillingness to act. A series of statements that makes it look as if Washington is more afraid of Israel taking action on Iran than it is of the nuclear threat itself has made the already difficult task of restraining Iran even harder.