Iran is playing a dangerous game of brinksmanship by threatening to break the terms of the nuclear deal it struck with the United States and other Western nations. Tehran’s recent declaration that it had breached the deal’s limits on the amount of enriched nuclear fuel it could possess is heightening the foreign-policy establishment's panic, in Europe and America, that President Donald Trump will plunge the world into war.As the sanctions reimposed by Trump after his withdrawal of the U.S. from the nuclear deal slowly bring Iran’s economy to a standstill, the Islamist regime appears to be mounting a two-pronged response. First, it aims to scare both the Europeans and the Trump administration into thinking that war is inevitable, and that when it comes, Trump’s decisions will be to blame. Second, it is betting that if it can hold out through 2020, Trump will be defeated, and it will be able to sit back and watch as any likely Democratic successor reinstates the nuclear deal and lifts the sanctions.America’s European allies are desperate to keep trading with Iran despite the sanctions, and to avoid any military conflict. That’s why they’ve floated the possibility of a barter-trade agreement that would in theory allow European companies and state entities to trade with Iran without falling afoul of the U.S. sanctions, which deny companies that do business with the Islamic republic access to the U.S. financial system. But few in Europe or Iran give any such agreement much of a chance of happening.Instead, Iran is ramping up its provocations. The Iranian Revolutionary Guard Corps — the entity at the heart of the regime’s efforts to finance international terrorism — has engaged in various acts of violence, including the shooting down of an American drone aircraft and the sabotage of two foreign oil tankers in the Gulf of Hormuz. Trump has, thus far, refused to take the bait, aware that it’s not in his interests to be dragged into an unpopular war or to deal with the pain that Iran’s terrorist auxiliaries could possibly inflict on U.S. and allied targets.Trump’s decision to back away from military retaliation on Iran after the drone was shot down was widely criticized as showing his lack of decisiveness. But by opting to increase sanctions rather than responding with force, he has actually weakened Iran’s hand: A military conflict was exactly what Tehran wanted, provided that it didn’t escalate to an all-out war that could endanger the regime’s hold on power.If Trump is not suckered into a no-win military exchange, that leaves Iran’s leaders back where they started: fully aware of the heavy toll that sanctions are taking on the country’s already shaky economy, and of the need to proceed with caution.Yes, the ayatollahs and the IRGC can still hope that if they hold out another 16 months, Trump will lose the White House and all their problems will be solved. Given that Trump trails all the major Democratic presidential contenders in head-to-head national polls, and that every one of the Democratic candidates save for New Jersey senator Cory Booker has pledged to return the United States to the nuclear deal, waiting the president out may seem like a wise strategy.But the Iranians should be wary of putting all their eggs in this basket.For one thing, despite the assumptions on the part of Trump’s foes that the 2016 election was a fluke that cannot be repeated, there are objective reasons to believe that he has at least an even chance of being reelected.For another, it may not be possible for Iran to make it through January 2021 without either bowing to Trump’s demand for a renegotiation of the nuclear deal or starting a conflict with unknowable consequences. With the country’s domestic economy tottering and its ability to fund its terrorist allies dwindling as a result of the sanctions, 19 months may simply be too long to wait.If Trump keeps his nerve and implements measures that cut off Iran’s last foreign economic lifelines, Iran's prospects remain grim -- its population is already languishing under the incompetent rule of an oppressive theocracy. That explains Iran’s brinksmanship. But the country’s leaders also know that blowing up the nuclear accord, as they continually threaten to do, will only push the Europeans reluctantly into Trump’s arms and worsen Iran’s economic plight.So the Iranians are left with the one option they continually say they will not consider: slinking back to the negotiating table to change the nuclear agreement.They were in more or less the same situation in 2013, when international sanctions had them backed into a corner. But, fortunately for them, President Obama and Secretary of State John Kerry were both ideologically committed to a rapprochement with Iran and also desperate for a deal at any price. That enabled the Iranians to keep their nuclear program and advanced-research capability while squeezing sunset clauses out of the Americans that will, within a relatively short period of time, allow them to resume their march toward a nuclear weapon without any legal impediments. Obama’s pact also didn’t address the problems of Iran’s illegal missile tests, its status as the world’s leading state sponsor of terror, or its ambitious military adventures in Syria and elsewhere.But Iran’s leaders must also understand that the West will never acquiesce to an Iranian nuclear weapon, which would pose a deadly threat to the security of the West and allies such as Israel and Saudi Arabia. Even if Trump had never been elected, sooner or later the United States was always going to have to demand the rescinding of the sunset clauses.The Iranians have good reason to think they can get a better deal in a renegotiation of the nuclear pact with any of the Democrats running against Trump. But their odds of saving some of the gains — nuclear, financial, and in terms of regional power — that Obama gave them may actually be better in the next year than in the years that follow.Despite Trump’s bluster and the presence of Iran hawks such as Secretary of State Mike Pompeo and national-security adviser John Bolton in his orbit, the administration’s goal is re-negotiation of the nuclear deal, not necessarily regime change. Trump has shown in his dealings with North Korea that he’s willing to be generous to those who pay him the compliment of coming to the negotiating table. And the alternative gamble — hoping Trump loses in 2020 — may provide only a Pyrrhic victory at best, if the interim 19 months of ever-increasing economic and diplomatic pressure do the kind of damage to the regime that it can’t afford or subsequently repair.If the Iranians are smart, they’ll take Trump up on his offer and start talking now.