One of the more amusing things to see in journalism is for committed liberals who didn’t work for Ronald Reagan, who didn’t vote for Ronald Reagan and who were fiercely critical of Ronald Reagan to invoke his name in order to instruct conservatives on how to better understand Ronald Reagan.

The most recent example of this is E. J. Dionne, Jr. of the Washington Post, who argues in his column that Barack Obama’s Iran strategy parallels Reagan’s approach to Mikhail Gorbachev in the 1980s. In fact, the lessons are exactly the opposite.

For all the criticisms of the left against Reagan that he was a rigid ideologue, he was, in fact, a man who was quite willing and able to adjust his views in light of shifting circumstances. That is precisely what he and Margaret Thatcher did in the case of Mr. Gorbachev.

To their credit, both Reagan and Thatcher were dedicated anti-Communists. They understood the evil nature of the Soviet regime and they took a hard-line stance against it for most of their careers. But equally to their credit, they saw that Gorbachev was someone with whom, in Thatcher’s words in 1984, “We can do business together.” And they did. Both Reagan nor Thatcher were able to revise their assumptions based on new facts, new actors on the world stage, and new opportunities. They were not dogmatists.

Mr. Obama, on the other hand, most assuredly is. He has been ideologically committed to a rapprochement with Iran even before he was elected president; it has been his foreign policy holy grail for his entire tenure. Nothing was going to keep him from striking a bargain with which he was obsessed. (It explains in part why the president was so passive during the Green Revolution in 2009, essentially siding with the Iranian regime over the democratic movement seeking to topple it.)

And here’s a key difference between Reagan and Thatcher and Obama. The former revised their approach based on an accurate assessment of Gorbachev and, therefore, the Soviet regime he ruled. Mr. Obama, on the other hand, was determined to strike a deal with Iran despite there being no compelling evidence that the basic nature of the regime has changed. If anything, in recent years Iran has acted more aggressively and destructively. Consider just a partial review of Iran’s record: support for the butcher in Damascus, Bashar al-Assad and the Shi’ite Houthi militia that seized Yemen’s capital in September; destabilization of Iraq and subversion of the broader Middle East; unmatched aid and succor to terrorist groups (including Hezbollah, several Iraqi Shia militant groups, Hamas, and the Palestine-Islamic Jihad); defiance of U.N. resolutions; white-hot hatred for Israel and the United States; and repression at home. This New York Times story, published just last month, reported on the Obama administration’s own State Department’s annual report on terrorism. According to the Times:

Iran continued its “terrorist-related” activity last year and also continued to provide broad military support to President Bashar al-Assad of Syria, the State Department said Friday in its annual report on terrorism.

The assessment suggests that neither the election of President Hassan Rouhani nor the prospect of a nuclear accord with the United States and its negotiating partners has had a moderating effect on Iran’s foreign policy in the Middle East.

“In 2014, Iran continued to provide arms, financing, training and the facilitation of primarily Iraq Shia and Afghan fighters to support the Assad regime’s brutal crackdown,” the report said… it paints a picture of an aggressive Iranian foreign policy that has often been contrary to the interests of the United States.

The State Department report itself states “Iran’s state sponsorship of terrorism worldwide remained undiminished” in 2014. Contrary to what Mr. Dionne claims, then, Barack Obama is all about trust and completely indifferent to verify. The president was determined to strike a deal with Iran, any deal, for the sake of a deal. The Iranians, knowing this, were able to win one concession after another from the president. It was an astonishing act of abdication and surrender, the product of an unusually adamantine and doctrinaire mind.

The comparison between Reagan and Gorbachev and Obama and Iran, then, isn’t only superficial. It makes precisely the opposite point claimed by the partisan progressives who make it. Mr. Reagan negotiated from a position of strength and operated within the four corners of reality; Mr. Obama negotiates from a position of weakness and operates in a world of his own imagination.

Ronald Reagan was a man of deep and admirable convictions, but his mind was far more supple and empirical than the left ever acknowledged. It was a far more supple and empirical mind, it turns out, than Barack Obama’s.