Since the 1960s, when Israel began equipping itself with U.S.-made fighter jets, our air force commanders have always wanted us to buy the most advanced generation of planes made by the American defense industry. The reason was to maintain air superiority and an excellent ability to attack targets from above, a central tenet of military doctrine. One of the consequences is the need to allocate a large chunk of the Israel Defense Forces' budget to acquiring combat jets.

The price of American fighter planes has ballooned, and the value of the deals has risen accordingly. While the cost of a Phantom jet toward the end of the 1960s was less than $2 million, the price of an F-15I jumped to $43 million by the end of the 1990s.

As we speak, Israel is negotiating a deal with the United States to buy 75 stealth-capable F-35 fighter jets, whose cost is likely to reach $15 billion. As in the past, the decision on whether to do a deal will almost certainly be made by the air force and be adopted by policymakers. But this time ministers and MKs should take an interest in the matter because of the repercussions a deal would have on the state budget and the IDF's preparedness. They will discover that many questions hover over the decision to buy such an expensive plane (around $200 million each). When examining such a large deal, we must consider whether the benefit to the air force justifies the high price.

Experts' appraisal of the F-35 raises doubts when considering future missions. Experts claim that its maneuvering capability is quite poor, perhaps worse than planes that flew missions over Vietnam. Its maximum speed is 1.6 times the speed of sound; the F-15 can reach 2.5 times. Yet the plane's biggest problem is probably its miserable payload. To prevent it from being picked up by radar, its munitions must be carried inside the aircraft. As a result, it holds just two bombs, each weighing one ton. An F-15, for instance, can carry a payload eight times as high.

Experts are convinced the F-35's maneuvering capability does not ensure that it will be able to evade enemy radar. As such, its ferry range is 1,800 kilometers, which means the plane can't fight a mission to Iran without refueling in midair. This is in contrast to the F-15's ferry range, which is four times as large.

All these factors lead us to wonder whether the air force's future missions can be executed with its current planes, or with the new line of fighter aircraft, whose prices are much lower (like the F-15 Silent Eagle, which sports impressive maneuvering capabilities). In any case, air forces around the world are increasingly opting for unmanned aircraft. Thus, it would be ill-advised to buy such expensive planes just to preserve the air force's prestige. If the main rationale for buying the new plane is to attack targets in Iran, this does not square with the fact that most of the plane's features make this task harder to carry out.

Before approval is given to allocate the $15 billion, the ministers and MKs should try to study the issue rather than blindly trusting whatever the IDF decides, as has always been the case.