Almost no one accepts Iran’s denials of its quest for nuclear weapons anymore, certainly including President Barack Obama, who said this week he has “Israel’s back” in any coming conflict.

Assuming anyone believes that promise, which is hard to do because he retreated from it in a subsequent news conference.

A war-weary American public shies from any new confrontation, but the decision very likely will not be up to us. The Islamic regime has been building long-range missiles with North Korean help for years, and there’s no reason to acquire such offensive weaponry without something worthwhile to put on it.

The Associated Press reported this week that foreign diplomats who are nuclear energy experts qualified to work with the U.N.’s International Atomic Energy Agency said current efforts to clean up an Iranian nuclear facility with bulldozers may indicate an attempt to hide weapons research in advance of new inspections.

The AP reported, “Two of the diplomats said the crews at the Parchin military site may be trying to erase evidence of tests of a small experimental neutron device used to set off a nuclear explosion. A third diplomat could not confirm that, but said any attempt to trigger a so-called neutron initiator could only be in the context of trying to develop nuclear arms.”

In fact, Iran already may have the bomb. Hans Ruehle, head of planning for the German defense ministry from 1982 to 1988, said this week that “by now, several intelligence agencies assume that North Korea in 2010 indeed performed one nuclear test for Iran.”

Iran’s president, Mahmoud Ahmadinejad, who has called for the destruction of Israel, also has demanded “a world without America,” and thousands of Iranian-built IEDs — the roadside bombs that have killed or wounded so many U.S. and allied troops — have been sent into Iraq and Afghanistan, along with tons of other weapons.

Obama seems to believe, despite a flood of contrary evidence, that “diplomacy” and new economic sanctions will dissuade a group of religious zealots who proclaim their faith that their legendary savior, the “Twelfth Imam,” will return soon to institute worldwide Islamic rule.

But Israel — a tiny democracy in a sea of tyranny, including nations where “The Protocols of the Elders of Zion” remains a best-selling book — can’t ignore Tehran’s oft-stated goals.

As President Benjamin Netanyahu said in a speech Tuesday to the American-Israeli Public Affairs Committee’s annual convention, “Unfortunately, Iran’s nuclear program continues to march forward … We’ve waited for diplomacy to work. We’ve waited for sanctions to work. None of us can afford to wait much longer. As prime minister of Israel, I will never let my people live in the shadow of annihilation.”

He even went so far as to say, “Never again.” If you don’t know what that means, go look up “the Holocaust.” A nation founded in part as a refuge from genocide isn’t going to be willingly subjected to it again.

In its 1981 attack on the French-built Iraqi Osirik reactor and the 2009 strike on Syria’s Al-Kibar North Korean-built nuclear production site, Israel has proved it will take decisive action when its survival is threatened.

A military strike bears incredible risks, including that Iranian capacity to produce a bomb will survive it, and the desire for revenge will lead to its inevitable use.

Assuming an effective strike, however, the price of oil will still soar, not only because of supply restrictions created by the conflict but because the so-called “risk premium” on future production will fly through the roof. No one knows how high the cost will go or how long the situation will last.

Finally, unless a revolution occurs in Iran, the nation will return to its efforts to build a warhead, leading to calls for further action in future years.

The consequences of inaction, however, are daunting, too.

A nuclear Iran could resort to unrelenting blackmail against neighboring states. And the dangers of a nation already bearing the reputation of “the principal state sponsor of terrorism” furnishing its clients with bombs would be substantial. One does not need a rocket to deliver a bomb to a U.S. city, just a cargo ship or a truck.

Second, Iran’s neighbors, many of whom could easily afford nuclear weapons technology, would be driven to acquire their own warheads, setting off a regional arms race.

Even if Iran didn’t use its bombs, it would be emboldened by them to increase its efforts to spread terror abroad. It already has sponsored lethal attacks in Africa, Europe and South America, and we can expect such violence to increase greatly.

So, there may not be much increase in long-term security from an attack (unless it results in regime change in Iran), but there’s no gain from refraining if the mullahs cross the nuclear threshold, either.

M.D. Harmon, a freelance writer, is a retired journalist and military officer. He can be contacted at: [email protected]