The simplest and cheapest — and therefore most popular — approach on Iran is to talk the country out of making nuclear weapons. This is silly.

The Iranian regime wants them, laughs at Western threats and awaits the next American president (no prizes for guessing whom it prefers) in the hopes he’ll follow a surrender strategy.

Iran won’t be bought off; it merely seeks to buy time.

Attacking Iran’s nuclear facilities might one day be necessary, but it won’t be easy. There’s too much to destroy, and Iran would have the knowledge and equipment to rebuild.

The cost of such an attack — which could include Iranian missile attacks on Israel, rocket barrages from Hezbollah and Hamas, heightened global terrorism, an Iranian campaign to destabilize Iraq and Afghanistan, and higher oil prices — would also have to be taken into account.

That list doesn’t make the cost of an attack too high if Israeli leaders believe the nation’s very existence is at stake. (In fact, research indicates the direct cost to Israel is quite sustainable.) Nevertheless, while an attack might be necessary, it surely isn’t preferable.

Is there anything else that can be done?

Regime change is a dream. The Islamic government is too deeply entrenched and armed to be overthrown; no revolutionary movement is in sight. The opposition reform faction is too weak, divided and demoralized — even if it has great popular support.

There remains the option of faction change. All Iran’s leaders are radical; all would like to see Israel destroyed. But how much would another leader risk in order to try?

Iranian President Mahmoud Ahmadinejad is so extreme, adventurous, demagogic and seemingly irrational that his threat to use nuclear weapons against Israel is credible, forcing Israel to attack. Others, such as Supreme Leader Ali Khamenei, former President Akbar Hashemi Rafsanjani and parliamentary Speaker Ali Larijani (whom Ahmadinejad fired as a nuclear negotiator) are also bad guys — but less mad.

Khamenei will use Ahmadinejad unless the price of his behavior becomes too high. But he and the rest know Ahmadinejad uses demagoguery, even to the point of risking war with Israel and the United States, because he wants all the power for himself and for his increasingly powerful friends in the Islamic Revolutionary Guard Corps.

In comparison, Rafsanjani wants nuclear weapons, but also good commercial relations with the West. He’d like to see Israel wiped off the map, but he isn’t going to be the one to do it.

Thus a power struggle rages in Iran, with next year’s presidential election serving as a key battle. Ahmadinejad’s critics use everything to discredit him, including his economic mismanagement and provocative deeds.

They should be helped. Pressure against Iran should be heightened and tightened; the possibility of military conflict should be a constant threat. It should be made clear that Ahmadinejad and his allies are more dangerous to Iran’s prosperity and the regime’s survival than to Israel or the West.

That’s why talk about direct negotiations or concessions is especially dangerous now. This strengthens Ahmadinejad and makes an eventual Israeli attack, with resulting confrontation, more likely.

To avoid war, Iran must be isolated and Ahmadinejad must be boycotted. It should be made clear that he’s leading Tehran toward disaster, one that a more reasonable leadership can avoid. The West must indicate that if the right person wins the election, direct talks could happen.

There are dangers here for Israel if the West accepts a radical Iranian regime with nuclear weapons. But remember these points:

n Israel may attack Iran’s installations at some point without real Western support.

n The West won’t do much more than it is doing now to stop Iran from succeeding.

n If the West doesn’t like this outcome, it had better give Israel enough to avoid it happening. More thought should be given to “appeasing” Israel by meeting its security requirements.

n An Israeli military campaign isn’t going to stop Iran from continuing its effort, no matter how much is destroyed.

So alongside this onrushing disaster, we need a realistic strategy to reduce the chance of an Iranian leader trying to use nuclear weapons against Israel.

Any Islamist government in Iran armed with nuclear weapons would be a disaster for the Middle East and for the West, not just Israel. Arab countries would then make their own deals with Tehran. The West would be paralyzed from acting effectively in the region. Arab-Israeli peace would be delayed by many decades. Oil prices would rise to higher triple digits. Revolutionary Islamist movements would grow, threatening every Arab regime.

A moderately radical leadership would have its flawed ambitions (read: nuclear weapons), but would be more easily talked out of going to the brink.

It’s better to deal with a moderately radical regime than what looks like a suicide bomber president forcing Israel to attack.

Barry Rubin is director of Global Research in International Affairs Center. This piece previously appeared in the Jerusalem Post.