Bloomberg | Eli Lake: President Donald Trump�s decision to part ways with his national security adviser, John Bolton, was overdetermined. They disagreed on Afghanistan. They differed on North Korea. There was tension between them over Venezuela. They couldn�t even agree on whether Bolton quit or was fired.

Their most significant dispute, however, was on Iran. Bolton favored completely abandoning the 2015 nuclear deal negotiated under former President Barack Obama and pressed for maximum pressure on Iran�s leaders. Along with Secretary of State Mike Pompeo, Bolton helped persuade Trump earlier this year to retain a U.S. military presence in Syria to counter Iran�s Revolutionary Guard Corps.

Trump has supported maximum pressure, but he has also flirted lately with diplomacy. At the Group of Seven meeting in France last month, the president pared down his administration�s initial 12 conditions for lifting sanctions on Iran to just three. While he has always left the door open to talks, Trump has been musing about this idea more openly and more frequently. It nearly happened at the G-7, when Iranian Foreign Minister Javad Zarif was invited to the summit by French President Emmanuel Macron. Bolton, senior U.S. officials told me, learned about his visit from the Israelis.

The prospect of Trump meeting with Iranian President Hassan Rouhani came up at a news briefing Tuesday with Pompeo and Treasury Secretary Steve Mnuchin. When asked if Trump could meet with Rouhani later this month at the U.N. General Assembly, Pompeo said: �Sure. The president has made it very clear: He is prepared to meet with no preconditions.�

To date, the Iranians have not agreed to any kind of meeting. Zarif has said the U.S. must lift sanctions before such a parley. Rouhani offered Obama � who pursued an accord with Iran throughout most of his presidency � only a brief phone call.

Nonetheless, Bolton�s exit could pave the way for the Trump dream of a U.S.-Iran summit. Zarif himself has made Bolton the centerpiece of his propaganda campaign. He blamed Bolton, but not Trump, for the increased tensions between his country and America, and Zarif�s allies in Washington have already applauded the end of the Bolton era. On Tuesday, the president of the National Iranian American Council Tuesday praised Trump. �We congratulate President Donald Trump on what may become the best decision of his Presidency,� said Jamal Abdi. �This single move dramatically reduces the chances of a new, catastrophic war in the Middle East.�

Trump has heard this argument from elements of the right as well. Fox News host Tucker Carlson ranted in June that Bolton was a �bureaucratic tapeworm.� Republican senator Rand Paul has offered his services as a back channel to Iran to help establish negotiations.

Of course it�s preposterous to argue that Bolton, who served Trump for less than a year and a half, is responsible for U.S. tensions with a country that been attacking American citizens and soldiers for 40 years. The issue is what the U.S. should do about this state of hostilities.

That�s why Trump�s frustrations with Bolton count as ironic. In 2017, the president held a series of meetings with Bolton to get his perspective on leaving the Iran nuclear deal � undercutting General H.R. McMaster, who was then serving as his national security adviser. McMaster wanted to keep the deal and pressure European allies to help renegotiate it and make it stronger.

Now it appears that Trump has buyer�s remorse. While he would never acknowledge it, Trump is basically pushing for a bargain very similar to the one that he criticized Obama for negotiating. Trump is free to appoint a national security adviser who shares his new position � and whoever takes the job will be safe until the president inevitably changes his mind.