One of the most frightening things I’ve read in a long time was an interview with Home Front Defense Minister Avi Dichter last week in which he asserted that Israel would need American help for any military strike against Iran’s nuclear program. “We have the capabilities of a state. But the US has the capabilities of a superpower,” he explained. “Iran is a regional Muslim power from both a military standpoint as well as from the standpoint of its scientific and technological capabilities.”Actually, my first reaction wasn’t fear, but outrage. For while Iran today is indeed a regional power, a few decades ago, so was Egypt. In fact, by almost any measure, the balance of power between Israel and Egypt then was far more lopsided in Egypt’s favor than today’s balance of power is with Iran. Nevertheless, Israel managed to win three solo wars against Egypt from 1948-1973. So why should it be incapable of doing today what it clearly was capable of doing back then?Consider, for instance, the difference between today’s situation and 1967. Back then, America refused to sell most types of weaponry to Israel; today, Israel is generously supplied with top-of-the-line American arms. Back then, Egypt fought in alliance with Syria and Jordan, both of which fielded powerful armies of their own; Iran’s likely allies boil down to Hezbollah, Hamas and Islamic Jihad, whose capabilities, while non-negligible, pale beside those of Syria and Jordan. Back then, Egypt and Syria were both clients of a superpower (the Soviet Union), whereas Israel lacked superpower backing; today, it’s Israel that has superpower backing, while Iran makes do with lukewarm support from lesser military powers like Russia and China. Finally, Israel today has three times the population and twice the GDP that it did in 1967, giving it far more men to put under arms and money with which to equip them. In short, back in 1967, a smaller, poorer, worse-armed Israel with no superpower backing could nevertheless defeat a regional power with formidable allies and superpower backing all by itself. But today, according to Dichter, a much bigger, richer, better-armed Israel with superpower backing is incapable of fighting unaided against a regional power with no state allies and no superpower backing. Objectively speaking, it sounds ridiculous; hence my outrage at hearing a top defense official spout it.But it didn’t take long for fear to set in – because regardless of the objective balance of power, an army that believes itself incapable of winning almost certainly will be. And while it’s possible that Dichter doesn’t represent the defense establishment’s consensus view, judging by his record, he is one of this establishment’s least defeatist senior officials: As Shin Bet security service director from 2000-2005, not only was he a major architect of the counterterrorism strategy that defeated the second intifada, but he pushed this strategy in the teeth of objections from Israel Defense Forces officers who insisted – wrongly – that “there is no military solution to terror.” In contrast, many senior IDF officers argued against a major military operation in West Bank refugee camps (where terrorist groups were largely based), issuing panicked warnings that it would result in hundreds of dead soldiers. In reality, Israel lost 30 soldiers in Operation Defensive Shield in 2002 – less than a quarter of the 132 Israelis killed by Palestinian terrorists in a single month before the operation. Senior army officers similarly warned that a major military operation against Hamas in Gaza would result in hundreds of dead soldiers; in reality, Israel lost exactly 10 soldiers in Operation Cast Lead in 2009, four of them to friendly fire. And today, senior IDF officers still insist there is “no military solution” to terror from Gaza, even though the IDF itself decisively disproved this theory in the West Bank just a few years ago. I’m all in favor of senior defense officials eschewing reckless overconfidence; the Second Lebanon War of 2006 amply showed how dangerous that can be. Even against a third-rate opponent like Hezbollah, victory is impossible if defense officials neglect the basics: a sound battle plan, proper training and good logistics. But at the same time, there’s no point in having an army at all if you’re afraid to use it when truly necessary. And it’s hard to think of a greater necessity than stopping Iran’s nuclear program: Defense Minister Ehud Barak exaggerated only slightly when he said “The [Iranian] sword hanging over our neck today is a lot sharper than the sword that hung over our neck before the  Six-Day War.”The danger posed by defeatism is a recurring theme in Jewish history (though in fairness, so is the danger of overconfidence). The first example, as Israel Harel noted in Haaretz a few weeks ago, dates back to right after the exodus from Egypt: Spies sent to Canaan in advance of a planned Israelite conquest returned to say the Jews couldn’t possibly win, because the people of the land were “giants; and we were in our own sight as grasshoppers, and so we were in their sight.” God finally solved that problem by making the Israelites wander in the desert for 40 years until the entire generation had died, after which a new, less defeatist generation accomplished the conquest fairly easily. Today, however, Israel can’t afford to wait 40 years. Barring unforeseen developments, Iran’s nuclear program could hit the point of no return as early as this spring, requiring Israel to choose between military action and a nuclear Iran. And as I explained in this column three weeks ago, should military action be necessary, Israel will almost certainly have to do it without American help.From a strictly military standpoint, Israel probably has the capacity to do the job. The question is whether our political and military leaders can find the courage to use this capacity if necessary. For if the grasshopper mentality prevails instead, the result is liable to be a nuclear Iran.And however intimidating Iran is as a nonnuclear regional power today, it will be far more dangerous as a nuclear one.The writer is a journalist and commentator.