If the United States and its partners do not stand firm in the coming days and years, Israelis feel they may be left alone to face the ayatollahs.
Israel is not at the table negotiating the deal on Iran's nuclear programme. Yet it is Israel's national security, perhaps more than anyone else's, that will be affected. Threatened by Iran's nuclear and hegemonic ambitions, Israel and most of its Arab neighbours question whether the expected agreement will stem either.
The choice is not between a good deal and a bad deal. A good deal -- permanently rolling back Iran's nuclear capacity, as was done in Libya -- is no longer possible. The question is whether the deal is acceptable, given the confines of the framework agreed in April.
That framework in effect legitimises Iran as a nuclear-threshold state and focuses on stopping it from crossing that threshold. In the first decade the deal limits Iran's capacity to quickly make enough nuclear material for a weapon. But in the second decade Iran is allowed to reduce its breakout time almost to zero, as restrictions on enrichment and stockpiling of uranium expire.
Iran's nuclear threshold status could trigger nuclear proliferation. Regional rivals, not least the Saudis, may race to catch up. It could also embolden the Iranians to advance their radical and sectarian agenda. In addressing these risks, the context of the deal matters no less than its fine print.
The six world powers negotiating with Iran should insist on certain critical elements: anytime, anywhere inspection and verification; irreversible conversion of excess enriched material in Iran; significant restrictions on research and development relating to centrifuges; a clear and binding pathway to resolving concerns expressed by international inspectors about the possible military dimensions of Iran's programme. Sanctions relief should be phased over years and be conditional on Tehran meeting these requirements.
But that is not enough. The key to stopping Iran from crossing the threshold at short notice is deterrence. Most of all, the U.S. needs to make clear there will be punishing consequences for violations. In addition, the international community should formally affirm its determination to prevent Iran from acquiring enough fissile material for a weapon, even after the restrictions lapse. The U.S. should also adopt a tough stance against Iran's hegemonic regional ambitions to reassure traditional allies who have lost faith in American political will to guarantee their security.
Unfortunately, U.S. deterrence has been badly eroded of late, both due to its reluctance to project power in the region, and its overeager approach to negotiating with Iran. Doubts about U.S. deterrence are only reinforced by the administration's insistence that there is a binary choice between a deal soon and war -- a self-defeating assertion which implies that it is the White House, rather than Tehran, that is most likely to be deterred from pursuing its objectives by the prospect of war.
Viewed from the region, one thing seems obvious: the best chance to prevent Iran from acquiring the bomb comes if the U.S. reasserts its willingness to use military force. While Ali Khamenei, Iran's supreme leader, has had no qualms stating his red lines, it has not been clear what the deal-breakers would be for those negotiating with him. Yet if such limits were set, they could be insisted upon. With the pressure of sanctions and a U.S.-led posture of deterrence, the western negotiators could credibly make clear that they are resolute, patient and will not accept a deal if their terms are not met.
Even as negotiations were under way, Israelis have watched Mr. Khamenei tweet nine "key questions about the elimination of Israel" (the third was: what is the proper way of eliminating Israel?). If the U.S. and its partners do not stand firm in the coming days and years, Israelis feel they may be left alone to face the ayatollahs -- enemies who might one day wield the ultimate weapon.
Brig. Gen. Michael Herzog, IDF (Ret.), is The Washington Institute's Milton Fine International Fellow. He previously served as head of the IDF's Strategic Planning Division and chief of staff to Israel's minister of defense.