If finally compelled to do so, Israel is able to destroy the Iranian nuclear weapons program, even if at breathtaking risk. Whether it succeeds or not, it faces yet another existential military problem, less immediate and on a different register, in regard to which it has made the wrong choice.

Though history may never repeat itself exactly, it does have affection for certain themes. One of these is that of a nation suicidally disarming because it rests upon the laurels of the past, or believes in the satisfying delusion that by intellectual formulation it can safely predict the future intentions and capabilities of rivals and enemies.

Israel remained so intoxicated by its brilliant victories in 1967 that, substituting excessive confidence for military prudence in the October War of 1973, it was very nearly destroyed. After shattering Israel's defenses, the Egyptian army halted only because of Israel's nuclear deterrent, after which the tide of war turned only because of an extraordinary American resupply effort authorized by President Richard Nixon, something that would hardly have been a certainty with President Obama.

Because Israel is understandably tired of war and wants to tend its vineyards, and because its military, like our own, has come down with a potentially fatal case of think-tankitis, it believes that, as expressed recently by its defense minister, "Wars of military versus military—in the format we last met 40 years ago in the Yom Kippur War—are becoming less and less relevant." Accordingly, it plans to cut its already diminished defense budget by more than one dollar in twenty; release a large proportion of career officers; and reduce further the numbers of its planes, tanks, and warships. The military will be shaped to fight Hamas, Hezbollah, and intifadas rather than the armies of Egypt, Syria, and whoever might join them.

The fallacy of this course is that, despite persistent internal troubles and external conflicts, the Arab confrontation states have coalesced at unlikely times and in unlikely circumstances. In 1948, obsessed with throwing off European domination and asserting independence, they nonetheless combined to make war on a nascent Israel, nearly wiping it out. In 1967, war hysteria from the Atlantic to the Persian Gulf reached such a frenzy of self-actualization that virtually no observers were confident that Israel would prevail—until it did. In 1973, against nearly all expectations, Egypt (always at the verge of bankruptcy) and Syria (always engaged in repression) nearly put an end to the Jewish State.

Although the divisions and travails of the Arab world retard coordinated action against Israel, the Arabs at times address these very problems by going to war against Israel. Egypt's army is now preoccupied, but hardly exhausted or depleted. If the Syrian regime holds, its army will be lean, habituated to action, and endowed with advanced Russian weapons. And other Arab and Islamic states—their militaries swelling and at rest—cannot be excluded from the strategical calculus.

Were Turkey to become sufficiently Islamist, which it may, its vast and modernizing armed forces would be a nightmare for now over-confident Israeli planners. Saudi Arabia's air force (soon 380 combat aircraft, primarily F-15s) is rapidly gaining on Israel (441 combat aircraft) in quantity and quality. Were the Saudis to take a Muslim-solidarity time-out with Iran and join Egypt, Syria, and perhaps even Turkey to defeat Israel in an air war, it would mean Israel's death.

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Yes, Israel's adversaries know of its nuclear weapons. in Egypt's case, even a conventional breaching of the Aswan Dam would have much the same effect as a nuclear attack. But if the Iranian nuclear program succeeds? If Saudi Arabia, in reaction, develops its own nuclear weapons? Or if jihadists take over Pakistan and its substantial nuclear arsenal? Then, having stalemated Israel's nuclear deterrent, the confrontation states—if they could achieve air superiority—would need only gnaw on Israel with ground forces for as long as it might take. Is it therefore time for Israel to slow the growth and development of its air force?

The diminution of Israel's tanks is nothing new. Ten years ago it had 4,000 in active inventory, now 480. Supposedly, nowadays only retrograde armies have tanks. Britain and France, for example, have token forces of 227 and 254 respectively, whereas Syria has 5,000. This is because "smart" weapons carried by infantrymen, light vehicles, and aircraft can make quick work of them. However, with air dominance, such weapons cannot be launched at one's tanks by enemy planes. With appropriate heavy artillery, also much out of fashion, and anti-personnel ammunition for tanks, infantry is similarly disempowered. Thus freed, the tank is an agile combination of mobile artillery, armored fighting vehicle, and personnel carrier able to execute the broad strategic movements that win conventional wars, especially in the deserts of the Middle East or on the plains of Central Europe, where the field of maneuver is hospitable to quick and decisive strokes.

Israel's leadership is canny, as the country's survival attests, but it doesn't always know best. Prior to the near-defeat of 1973, a number of analysts had strong indications of impending catastrophe. Among those who listened (to even a lowly private who accurately predicted a massive surprise attack when the weather cooled), were David Elazar, the chief of staff, Moshe Dayan, minster of defense, and Golda Meir, the prime minister—all of whom refused to heed correct and timely advice.

After the war, Elazar was forced to resign, Dayan suffered a nervous breakdown, and Golda Meir's government fell, because so nearly did Israel. In relying upon beliefs of the moment and conceptualizing away the threat, they had foresworn the extra margin of safety that was their duty to uphold. Forty years later, Israel must not make the same mistake. Given its plans, one would think it was sitting safely somewhere in the Dakotas. But it isn't, and such a small country—with so many large and powerful enemies and so little strategic depth—simply cannot be too cautious.