The idea that Israel might lose a conventional war seems ridiculous now, but the origins of the Israeli nuclear program lay in the fear that the Arab states would develop a decisive military advantage that they could use to inflict battlefield defeats. This came close to happening during the 1973 Yom Kippur War, as the Egyptian Army seized the Suez Canal and the Syrian Arab Army advanced into the Golan Heights. Accounts on how seriously Israel debated using nukes during that war remain murky, but there is no question that Israel could consider using its most powerful weapons if the conventional balance tipped decisively out of its favor.

Israel’s nuclear arsenal is the worst-kept secret in international relations. Since the 1970s, Israel has maintained a nuclear deterrent in order to maintain a favorable balance of power with its neighbors. Apart from some worrying moments during the Yom Kippur War, the Israeli government has never seriously considered using those weapons.

The most obvious scenario for Israel to use nuclear weapons would be in response to a foreign nuclear attack. Israel’s missile defenses, air defenses, and delivery systems are far too sophisticated to imagine a scenario in which any country other than one of the major nuclear powers could manage a disarming first strike. Consequently, any attacker is certain to endure massive retaliation, in short order. Israel’s goals would be to destroy the military capacity of the enemy (let’s say Iran, for sake of discussion) and also send a message that any nuclear attack against Israel would be met with catastrophic, unimaginable retaliation.

But under what conditions might Israel start a nuclear war?

Nuclear Pre-emption

If a hostile power (let’s say Iran, for sake of discussion) appeared to be on the verge of mating nuclear devices with the systems needed to deliver them, Israel might well consider a preventive nuclear attack. In the case of Iran, we can imagine scenarios in which Israeli planners would no longer deem a conventional attack sufficiently lethal to destroy or delay the Iranian program. In such a scenario, and absent direct intervention from the United States, Israel might well decide to undertake a limited nuclear attack against Iranian facilities.

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Given that Iran lacks significant ballistic missile defenses, Israel would most likely deliver the nuclear weapons with its Jericho III intermediate range ballistic missiles. Israel would likely limit its attacks to targets specifically linked with the Iranian nuclear program, and sufficiently away from civilian areas. Conceivably, since it would be breaking the nuclear taboo anyway, Israel might target other military facilities and bases for attack, but it is likely that the Israeli government would want to limit the precedent for using nuclear weapons as much as possible.

Would it work? Nuclear weapons would deal more damage than most imaginable conventional attacks, and would also convey a level of seriousness that might take even the Iranians aback. On the other hand, the active use of nuclear weapons by Israel would probably heighten the interest of everyone in the region (and potentially across the world) to develop their own nuclear arsenals.

Nuclear Transfer

One of Israel’s biggest concerns is the idea that a nuclear power (Iran, Pakistan, or North Korea, presumably) might give or sell a nuclear weapon to a non-governmental organization (NGO). Hamas, Hezbollah, or some other terrorist group would be harder to deter than a traditional nation-state. Even if a terrorist organization did not immediately use the weapon against an Israeli target, it could potentially extract concessions that Israel would be unwilling to make. In such a scenario, Israel might well consider using nuclear weapons in order to forestall a transfer, or destroy the enemy nuclear device after delivery. This would depend on access to excellent intelligence about the transfer of the device, but it is hardly impossible that the highly professional and operationally competent Israeli intelligence services could provide such data.

Why go nuclear? The biggest reason would be to ensure the success of the strike; both the device itself and the people handling the device would be important targets, and a nuclear attack would ensure their destruction more effectively than even a massive conventional strike (which might well accompany the nuclear attack). Moreover, committing to the most extreme use forms of the use of force might well deter both the NGO and the originating state (not to mention any states that facilitated transfer through their borders; hello, Syria!) from attempting another transfer. However, the active use of nuclear weapons against a non-state actor might look to the world like overkill, and could reaffirm the interest of the source of the nuclear device in causing more problems for Israel.

Conventional Defeat

The idea that Israel might lose a conventional war seems ridiculous now, but the origins of the Israeli nuclear program lay in the fear that the Arab states would develop a decisive military advantage that they could use to inflict battlefield defeats. This came close to happening during the 1973 Yom Kippur War, as the Egyptian Army seized the Suez Canal and the Syrian Arab Army advanced into the Golan Heights. Accounts on how seriously Israel debated using nukes during that war remain murky, but there is no question that Israel could consider using its most powerful weapons if the conventional balance tipped decisively out of its favor.

How might that happen? We can imagine a few scenarios, most of which involve an increase in hostility between Israel and its more tolerant neighbors. Another revolution in Egypt could easily rewrite the security equation on Israel’s southern border; while the friendship of Saudi Arabia seems secure, political instability could change that; even Turkish policy might shift in a negative direction. Israel currently has overwhelming conventional military advantages, but these advantages depend to some extent on a favorable regional strategic environment. Political shifts could leave Israel diplomatically isolated, and vulnerable once again to conventional attack. In such a situation, nuclear weapons would remain part of the toolkit for ensuring the survival of the nation.

Conclusion

It is unlikely, but hardly impossible, that Israel could decide to use nuclear weapons first in a future conflict. The best way to prevent this from happening is to limit the reasons why Israel might want to use these weapons, which is to say preventing the further proliferation of nukes. If Israel ever does use nuclear weapons in anger, it will rewrite the diplomatic and security architecture of the Middle East, and also the nonproliferation architecture of the world as a whole.

Robert Farley, a frequent contributor to the National Interest, is author of The Battleship Book. He serves as an Senior Lecturer at the Patterson School of Diplomacy and International Commerce at the University of Kentucky.

This first appeared last month.