‘Fix or Nix” the Joint Comprehensive Plan of Action is a nice slogan. This approach might cause difficulties for Iran, which is not a bad thing in itself, but it will not put an end to Iran’s drive for a nuclear weapon. What needs “nixing” is not the JCPOA – a piece of paper – but the Iranian nuclear infrastructure. Only a credible military threat can cause Iran to back away from the path to a nuclear weapon.The nuclear deal signed with Iran in July 2015 is a charade and serves Iran’s goals. While it imposes restrictions on Iran’s stockpiles of uranium and its ability to enrich it for another decade, after its expiration Iran can go on with its nuclear program. Moreover, the agreement does not prevent further progress such as upgrading centrifuges. Similarly, additional work in the area of weaponization is allowed, shortening the breakout period in the future. In addition, the agreement permits Iran to deny effective inspection by declaring any site within its territory as military. Furthermore, the agreement ignores the issue of means of delivery, i.e. Iran’s missile program. Finally, the JCPOA does not to curb Iranian schemes for regional hegemony.Therefore, concerned parties, Israel in particular, demand to “fix or nix” the JCPOA. The Trump administration shares such concerns and even some European states seem to have second thoughts about the utility of the deal.Yet, fixing the agreement is hardly a realistic goal. Iran got a good agreement and has little incentive to change it. It signed the JCPOA to divert attention from the components of its nuclear program. A nuclear weapon is the indispensable insurance policy for the regime and for its freedom of action. A secondary goal was the removal of economic sanctions.Building an international consensus for revising the JCPOA, after its being heralded as a great achievement, is not easy and requires patient and hard diplomatic work.Furthermore, what seemed to be the leverage for bringing Iran to the negotiating table – economic pressure – is no longer existent. Any attempt to reinstate the international economic sanctions regime will take time. Russia and China will drag their feet and will try to limit the damage to Iran, as they have done before. Several states, European and Asian, which capitalized on the removal of sanctions to renew lucrative business connections with Iran will oppose the renewal of sanctions. Even if the US eventually succeeds in bringing reluctant states along to support a sanctions regime, this is a time-consuming process. The achievement of coordination for multilateral action has always been a complicated and lengthy exercise with no guaranteed success.Indeed, the history of international economic sanctions shows mixed results. Often, economic sanctions are preferred in order to show some international solidarity in the absence of willingness to take meaningful action. Yet, in those cases where economic pressure from the international community proved effective in changing policy, much time and patience was required.Time, however, is the commodity Iran wants more than anything. Time is needed to complete preparations for a nuclear breakout and for presenting the world with a fait accompli. The Iranians seek to gain time until the expiration of the JCPOA and until the determination of the international community to enforce sanctions dissipates.Yet, under duress Iran might opt for entering into endless negotiations to “fix” the JCPOA. The Iranian diplomats excel at procrastination. The many rounds of diplomatic bargaining will maintain a facade of international attempts to revise the nuclear agreement and prevent the effective alternative action. This is what Iran and many states might eventually prefer. Furthermore, the required revisions in the agreement may not be what is really needed. Therefore, efforts to “fix” the agreement might end up in economic sanctions accompanied by protracted and useless negotiations. Alternatively, it could lead to another flawed agreement.“Nixing” the JCPOA is attractive to its critics because it will deny legitimacy to the ayatollahs. Yet, Tehran might be pleased with the removal of restrictions and try a quick nuclear breakout. If this is not in the cards, it might decide to preempt “nixing” by offering negotiations for “fixing,” which will buy them time.Only a military threat or a military strike can bring closure of Iranian installations with military nuclear potential. Unfortunately, an Israeli military threat is nowadays no longer credible, even if the Jewish state has the capacity to deliver a blow to the key components of Iranian nuclear infrastructure. Under Trump, the threat of an American military strike is somewhat more credible, but it is not clear whether the American administration has reached the point where it is ready to use force to stop nuclearisation of Iran.Hopefully, Jerusalem’s dialogue with Washington will produce a more muscular American position. Israel should be warning Washington and other global actors that the nuclear program is too dear to the Iranian current political elite to be discarded unless Iranian leaders are led to understand that they imminently face a military attack. One way to do this is for Israel to bolster its military capability and credibility.The author is president of the Jerusalem Institute for Strategic Studies (www.jiss.org.il) and a Fellow at the Middle East Forum.