It didn’t come as a surprise when President Trump declared that he was pulling out of the Iran nuclear deal, unraveling the signature foreign policy achievement of his predecessor, Barack Obama. While it was long anticipated it plunges America’s relations with European allies into deep uncertainty. They have committed to staying in the deal, raising the prospect of a diplomatic and economic clash as the United States reimposes stringent sanctions on Iran. It also raises the prospect of increasing tensions with Russia and China, which also are parties to the agreement.Nevertheless, the withdrawal fulfills one of Mr. Trump’s oft-repeated campaign promises and brings the Iranian Ayatollah to the brink of Judgement Day. All know that the United States and its allies could not stop Iran from building a nuclear weapon under the structure of the current deal. Perhaps that is why the Obama administration refused to submit the deal to Congress as a treaty, knowing it would never get two-thirds of the Senate to go along. Just 21 percent of Americans approved of the deal at the time it went through, against 49 percent who did not, according to a Pew poll. The agreement “passed” on the strength of a 42-vote Democratic filibuster, against bipartisan, majority opposition. As such it’s questionable whether the deal had any legal force at all.President Trump has instructed the Treasury Department to develop additional sanctions against Iran, a process that could take several weeks. Under the financial sanctions, European companies will have between 90 days and 180 days to wind down their operations in Iran, or they will run afoul of the American banking system. The oil sanctions will require European and Asian countries to reduce their imports from Iran. With these Trump hopes and intends to be more forceful that with the Joint Comprehensive Plan of Action (J.C.P.O.A.), the official name of the deal, to signal to Iran a deterrence and to force it to comply.In my view President Trump was correct to declare that he was pulling out of the Iran nuclear deal. The way to fix relations between Iran and the rest of the world is to impose stiffer penalties on Tehran for its continued testing of ballistic missiles, more than 20 since the deal came into effect, and its increasingly aggressive regional behavior. In my view President Trump was correct assuming, that is, serious thought has been given to what comes next. If Iran is serious that they have not broken the deal they can now provide any evidence to prove the President incorrect in his allegations and assumptions. This is diplomacy. It is like a court room. If Iran doesn’t then they have settled the judgement against them and will have to live with new sanctions and increased anger from the Iranian population. If they wish to have these new sanctions lifted, then they will need to enter negotiations. That will be not be easy with Trump who will be more demanding than his predecessor Obama. The real problem with these approaches, both sanctions and written agreements, is that it they only treat symptoms of a problem. Any effort to counter Iran on the ground in its depredations in Syria and its militant proxies in Yemen, Lebanon, Gaza and elsewhere could mean fighting the very forces. New sanctions and new agreements are unlikely to prevent Iran from enriching as much material as likes or building missiles.At the same time as sanctions and if negotiating a new treaty, the Ayatollah and President in Iran must be made aware of the costs of their actions the same way for example Gaddafi of Libya was in 1986. A surgical strike, American or Israel, on Iran’s nuclear sites is one way. Following this the Ayatollah and President of Iran with pressure from the Iran population will get the message. The message is that the time for words are over and now its all action. Ordinary Iranians are already furious that their government has squandered the proceeds of the nuclear deal on propping up the Assad regime in Syria. Nor will it help Iran if it tries to start a war with Israel and comes out badly bloodied.The goal is to put Iran’s rulers to a fundamental choice. They can opt to have a functioning economy, free of sanctions and open to investment, at the price of permanently, verifiably and irreversibly forgoing a nuclear option and abandoning their support for terrorists. Or they can pursue their nuclear ambitions at the cost of economic ruin and possible war. President Trump’s decision to withdraw from the nuclear deal clarifies the stakes for Tehran. If the Ayatollah refuse, then Judgement Day has been raised.