Israel’s purchase of F-35 fighter jets exemplifies the fatal distortion of our military doctrine.

We are used to fighting huge but immobile Arab armies. In 1973, the Egyptian advance stalled a few dozen miles from Suez, not so much because of Israeli defense, but because the Egyptians utterly lacked mobility. Syria did not march half a million soldiers over the Golan Heights apparently out of concern that they would run away under Israeli fire. We have missed that the situation has changed drastically: Arab armies have become large, mobile, and motivated.

Israel’s luck in her major war was that the common Arabs did not want to fight. It was simply not their war. An Egyptian saying went that the Syrians wanted to fight Israel to the last Egyptian soldier. Everyone disliked Israel, but no one cared about the Palestinians; in fact, other Arabs hated Palestinians more than they hated Jews. But it is very different today. Europeans have passed the age of religious wars, and perhaps the age of nationalist wars is over, too. Who knows what they will be fighting over next time: Chinese knockoffs, football teams, or human rights. Arabs have just entered the cultural age of nationalist wars. Common Syrians might be mildly negative toward Israel in the way that Germans disliked Poles in the early 1930s; moderation of their beliefs is not the point. The problem is that nationalist feelings exist now which were nearly absent forty years ago, and such feelings can be quickly inflated and mobilized. Worse, nationalist sentiment is decreasing in post-Zionist Israel. The kind of patriotism that motivates people to fight is hard to find in a country whose population is one quarter Arab, 10% anti-Zionist haredim, a similar number of ultra-left peaceniks, and a few Russian anti-Semites with Jewish great-grandfathers. Still fewer people retain their fighting spirit amid the twenty-year-long peace talks and coexistence propaganda.

Arab armies have become huge, if not in their actual size then in their ability to conscript. In 1973, Syria amassed 150,000 troops. With its current population, Syria could probably conscript twenty times that number. In Israel, less than half of all males join the army.

Arabs have achieved mobility not by traditional means of jets, tanks, and APCs (though in every such category they vastly outnumber Israel). Instead, they have achieved the ultimate unmanned mobility, with rockets. A defenseless Israel faces crude Palestinian projectiles, the decent tactical arsenals of Hezbollah, mid-range Syrian SCUDs, and Iranian ballistic missiles. And yes, Israel is defenseless. Patriot and Arrow anti-missile batteries cannot be activated promptly enough in the event of a Syrian strike. Our arsenal of antimissiles is in any case far too small to prevail against the huge number of enemy missiles. The Iron Dome is too expensive, with too few installations to intercept a coordinated strike across the Lebanese border. Israeli cities, fuel depots, even military runways are completely unprotected against a surprise or massive strike. Such a strike would probably not come from Hamas, of whose territory we have good intelligence, but from Syria and Hezbollah, who can certainly mount an overwhelming missile strike against us. Would they be afraid of Israeli retaliation? Of course not. Those days are long gone. Israel lost her ability to deter Syria when we did not bomb Damascus in 1973. A country that shied away from carpet-bombing Lebanese and Gazan villages in 2006 and 2009; who would expect it to nuke Damascus?

The famous US-Indian air force games showed decisively, if indeed it was not self-evident, that quantity is more important than quality. IDF’s excellent training and IAF’s excellent capabilities can overcome the Arab numerical advantage only to a point. And the Arab quantitative edge could immediately be augmented by qualitative superiority if Saudi Arabia were to turn its weaponry against Israel. In the last twenty years, the Saudis have procured from the United States about ten times more weaponry than Israel.

Quality allows for theoretically spectacular strikes, which are not so spectacular in practice. Entebbe? Think Germany and Mogadishu: hostage rescues deep in foreign territory are not unusual. Entebbe was not tremendously more difficult. 1967? It was luck, pure and simple, that the Arabs left their airfields undefended—exactly the way IAF’s air bases lie open now. We created the myth of our military prowess, but the enemy may not believe it.

Back to F-35. Wars are not won by spectacular strikes any more than by public relations shows. Bombing the Syrian reactor was nice, and it was great PR, but it did not change the military equation. In the next war between Israel and Syria, neither side will use its nuclear weapons. Our problem is with Syria’s thousand mid-range missiles. If we preempt and destroy them, well and good, but what if Syria takes us by surprise, as it did in 1973? No amount of cutting-edge weaponry would solve that problem.

What can be done? The unpalatable answer has been well known since the Cold War. When the enemy has more weaponry than you can feasibly defend against, deterrence is the only answer. And to nationalistically-minded Arab crowds and apocalyptically-minded Muslim leaders, the only credible deterrent is mutual assured destruction. Far from humane and liberal, Israel must be mad: mad enough that the Arabs would expect us to nuke them if they launched a saturated missile attack or marched three million Syrians over the Golan Heights. Short of that, we are inviting their first strike.