Should Israel be in NATO
Bruce Riedel argues that unless Israel is reassured by the U.S. that its nuclear deterrent remains unmatched in the region, it will attack Iran. Such an attack, he writes, would be a "disaster in the making" and so he recommends extending the U.S. nuclear umbrella over Israel and admitting them into NATO.
The purpose of the U.S. "nuclear umbrella" was to 1. protect weaker countries from a nuclear threat; 2. prevent proliferation. Neither of these applies to Israel which is stronger than Iran and already has its own, vastly superior, nuclear arsenal. If Iran is not going to be deterred by Israel's arsenal, which could, according to Anthony Cordesman, likely kill between 16 and 28 million Iranians and end Iran as a functional political entity, then they're not going to be deterred by the U.S. either. Still, you could make the case that the U.S. should nonetheless extend the nuclear umbrella to Israel as an expression of support and a further warning to Iran not to push it.
NATO admission, though, is much more problematic, not least because it's hard to envision a single Western European member country (or, um, Turkey) being enthusiastic about the prospect. NATO was formed for a specific purpose, to defend Western Europe from a Soviet attack. The borders in this instance were clear, as were the combatants. NATO offered protection to nations that were, individually, weak before a much stronger conventional enemy. None of this applies to Israel. It is the stronger party - both vis-a-vis Iran and its non-state adversaries (Hamas, Hezbollah) - its borders are unsettled, and the combatants are not fixed armies but armed guerilla groups that blend into the populace of Israel's neighbors.
Admitting Israel to NATO would open up a host of questions. How, for instance, would NATO interpret Article V of its charter which stipulates that an armed attack on one will be deemed an attack on all? The language was invoked only once in the organization's history: on 9/11. Yet Israel suffers serious terrorist attacks on a more routine basis. Would NATO be bound to attack Hamas in Gaza or Hezbollah in Lebanon? Given how NATO has performed in Afghanistan, it's difficult to see them rushing into the Levant.