Iran's Nuclear Diplomacy: A Response from Israel

in Israel, unlike the West, there is no serious containment school, and any discussion of Israel’s response after the fact is, necessarily, highly speculative.

By Michael Herzog
Netanyahu Red Lines paper

From the perspective of those in Israel’s defence establishment and its decision-makers, Iran’s nuclearisation tops the list of threats to their country’s national security. Some, including Prime Minister Benjamin Netanyahu, even define the threat as ‘existential’. One should not underestimate this mindset in a nation whose collective consciousness has been shaped by historical persecution and a series of wars forced upon it by hostile neighbours. 

Israelis do not regard the challenge as being exclusive to them, and believe that it falls to the ‘free world’, under US leadership, to resolve it. At the same time, however, they see the threat to Israel as being far greater than that posed to any other regional or international actor. This is due to the potential marriage between WMD (Israelis have no doubt that Iran seeks a nuclear weapon) and the Iranian regime’s deeply felt ideological and theological hostility towards Israel. This hostility, coupled with its regional hegemonic ambitions, has already led Iran to target Israel through proxies – regionally and globally. There is a strong feeling that if the international community were to fail to put a stop to Iran’s nuclear ambitions, the burden would fall on Israel. The perception of waning US regional influence since the Arab Awakening has reinforced this concern.

The question is whether a nuclear-armed Iran would actually use its capabilities against Israel. Most Israelis agree that this is not an issue that should be put to the test. In either case, Israel believes that a nuclear-armed Iran would dramatically alter Israel’s strategic landscape by triggering a regional nuclear arms race, enhancing Iran’s position as a mainstay of radicalism, and allowing Tehran, under the shield of nuclear deterrence, to escalate its destabilising power projection. Further into the future, proliferation among non-state actors is also considered a threat.

For Israelis, the policy debate over Iran is therefore an acute, real-life issue, not a theoretical one. The consequences of any action to prevent Iranian nuclearisation are weighed carefully against the cost of inaction. For Israel, all options really are on the table.

Israel’s Response to a Nuclear-Armed Iran    

Iran’s nuclearisation would constitute a major defeat for Israel’s preventive policy and its ‘Begin doctrine’, which establishes the policy of denial of nuclear capabilities to regional actors who might use them to threaten Israel. Moreover, it would underscore the emerging perception of the US as an unreliable ally.

Indeed, Israel is wholly focused on prevention and will not so much as hint at an alternative, lest it be perceived internationally to be resigned to the idea of a nuclear-armed Iran, thereby also weakening the resolve of others. As such, in Israel, unlike the West, there is no serious containment school, and any discussion of Israel’s response after the fact is, necessarily, highly speculative.

In forecasting Israel’s possible use of military instruments ‘the day after’ Iranian nuclearisation, it would be necessary to consider why Israel failed to deter Iran from this course, given its determined commitment to prevention. In particular, it should be asked whether Israel would be surprised by an Iranian nuclear breakout, deterred, or faced with a closed operational window or a broader negative cost-benefit calculus. It should also be considered whether Iran would achieve break out under the cover of a diplomatic deal with the international community – a scenario of great concern to Israel.

Whatever the circumstances, if Israel made a calculated decision not to strike Iran before it became a nuclear-armed state, it is no more likely to take such action after this occurred. Whilst overt military action to roll back Iranian nuclearisation cannot be entirely ruled out, the potential gains from such action for Israel would probably diminish compared to pre-nuclearisation. Facing a nuclear-armed Iran, Israel is more likely to employ clandestine and covert intelligence and military tools.

If Israel were unable – and other states were unwilling – to roll back Iranian nuclearisation, it would have to adopt a policy of deterrence and containment.

Deterrence would rely predominantly upon Israel’s own strategic capabilities. Israel is unlikely to rely for its national security on a US deterrence umbrella. A regional nuclear arms race triggered by Iranian nuclearisation might force Israel to reconsider its long-held policy of ambiguity regarding its own strategic capabilities. Furthermore, Israel would probably not be deterred from striking Iran’s proxies – first among them Hizbullah – should they, emboldened by Iran’s nuclear posture, continue to provoke Israel and threaten its security.

Conversely, containment, including the continued imposition of international sanctions, would rely on the international community. Yet since Israel would have been vindicated in its belief in the inability of containment to check Iran’s ambitions, more weight would fall on deterrence.

The chapter discusses a number of tools of potential benefit to Israel in the face of a nuclear-armed Iran. These include informal alliances with Arab states which share Israel’s concerns, enhanced Israel–US co-operation, and the imposition of greater US and Western pressure on Iran. Yet in Israeli eyes, while realistic and desirable, these tools would have limited effect, since Arab states look set to restrain co-operation with Israel at least as long as there is no Israeli–Palestinian peace agreement in place, and the US would have lost credit for failing to stop Iran. Meanwhile, the chances of success in Israeli–Palestinian and Israeli–Arab peace-making would likely be diminished by Iran’s acquisition of nuclear weapons, which would strengthen the ‘resistance axis’ in the region and intimidate moderates. Facing such an enormous challenge with limited tools, Israel could be tempted to visit the option of regime change, to the extent that this is possible. 

It is hard to see direct diplomatic engagement developing between Israel and the current Iranian regime should Iran acquire the bomb. Indeed, given the high level of animosity, the chances of miscalculation between the parties would increase significantly, even if a channel of communication were established through a third party. 


A nuclear-armed Iran would require profound adjustments in Israel’s national strategic doctrine. The new strategic landscape would present acute conundrums, enhancing Israel’s need for peace with its neighbours, whilst also making this harder to achieve and increasing Israel’s dependence on an American ally rendered less reliable, with no good alternatives.

Brigadier General (IDF rtd) Michael Herzog is an International Fellow at the Washington Institute for Near East Policy and a Senior Visiting Fellow at BICOM (Britain Israel Communications and Research Centre). He previously served as head of Strategic Planning in the IDF and chief of staff to Israel’s minister of defence.       

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