As prime minister of Israel, David Ben-Gurion came to the conclusion that the Jewish state must maintain a “qualitative military edge” (QME) over its neighbors. The U.S. adopted this idea as policy in 1968, and Congress effectively made it the law in 2008 by passing a bill known as H.R. 7177. The Iran deal, by putting the Islamic Republic on the path to developing nuclear weapons, turns the idea on its head, as Aaron Menenberg writes:
H.R. 7177 . . . states that Israel must have “the ability to counter and defeat any credible military threat from any individual or possible coalition of states or from non-state actors.” That means that, if Iran gets a nuclear weapon, Israel must be able to counter and defeat a nuclear attack from Iran. At the same time, it must be able to counter and defeat simultaneous missile attacks from Hizballah, Hamas, and Palestinian Islamic Jihad, not to mention any ground attacks emanating from Lebanon, Syria, the West Bank, and Gaza. In addition, Israel must be able to sustain “minimal damages and casualties.” . . . It does not take a military expert to understand just how difficult—perhaps impossible—this objective is to achieve against a nuclear-armed Iran.
This is because, on a fundamental level, an Iranian nuclear weapon hollows out the purpose of Israel’s QME, which is to [compensate for] Israel’s lack of strategic depth. In a conventional war, Israel has a strong enough military and defense system in place to keep an enemy from getting inside Israel’s territory and exploiting that lack of depth. An Iranian nuclear weapon, however, overcomes Israel’s QME by placing all of Israel’s territory under existential threat. The QME is supposed to render Israel’s lack of territorial depth irrelevant, but Iran’s nuclear weapons program makes it relevant again by creating the ability instantly to target Israel’s entire population with—given its dense concentration within a compact territory—quite devastating results.