While the world deplores Russia’s war on Ukraine, a diplomatic debacle is unfolding at Vienna, where the Biden administration has been haggling over terms for re-entering a nuclear deal with Iran. This has put the administration in a position in which to gain an agreement it needs cooperation from the very tyrannies — Russia and China — that are our most dangerous adversaries. They and Iran are in cahoots.

That in and of itself flags the folly of America trying to squeeze back into the articles of appeasement from which President Trump withdrew America in 2018. The group dickering with Iran represents the five permanent members of the Security Council — Britain, France, Communist China, Russia, and America — plus Germany. 

All, including Russia, are needed at the table or the process unravels. The Iranians refuse to speak to the Americans, so President Biden’s envoys have been relying on intermediaries, especially Russia. Writing in National Review, Andrew McCarthy lays out the case that Russia’s lead negotiator, Mikhail Ulyanov, has been chief orchestrator of the recent negotiations.

Not only does Russia’s role augur a bad deal but with America desperate for a deal, the process itself has turned Mr. Biden’s envoys into Russia’s hostage. Desire for an Iran deal has translated into powerful incentives for the U.S. to water down its response to Russia’s growing threats and current onslaught against Ukraine.

It’s an all too convenient bit of timing for President Putin, that, after an impasse last year, the Iran parley resumed in November as the Russ strongman was assembling his forces on Ukraine’s borders. Secretary of State Blinken, concerned about Iran’s rising stockpile of enriched uranium, was left to wheedle for Russia’s help in pressuring Iran for a deal.

Following a meeting with Russia’s foreign minister, Sergey Lavrov, on January 21 at Geneva, Mr. Blinken told the press that Iran was “an example of how the United States and Russia can work together on security issues of shared concept.”  At the time, Russia was holding with Iran and China joint naval maneuvers in the Indian Ocean.

That followed a visit by Iran’s president, Ebrahim Raisi, with Mr. Putin at the Kremlin. In televised remarks, Mr. Raisi told Mr. Putin that it is time to confront America “with an increased synergy between our two countries.” Mr. Biden at that stage was reassuring Russia that the U.S. would send no troops to fight in Ukraine. Mr. Biden delayed sanctions against Russia only to implement them after Mr. Putin in late February launched his invasion.

We’ve been here before, during the Obama-Biden administration, when the opening of the original Iran nuclear talks in 2014 coincided with Mr. Putin’s initial bite out of Ukraine: the seizure of Crimea. Then, as now, Russia was needed at the table for P5+1 Iran diplomacy.

As the talks opened back then at Vienna, Ukrainian protesters at Kiev were completing their Maidan Revolution. Scores gave their lives to oust Ukraine’s president, Viktor Yanukovych, a puppet of Russia. He fled to Moscow. Within the week Mr. Putin began his armed grab for Crimea, then sent Russian forces into the Donetsk and Luhansk regions to stir up separatist conflicts in which more than 10,000 had died even before the current invasion.

I remember that timing overlap well, because during the early rounds of the original Iran nuclear talks, in mid-February and mid-March 2014, I was at Vienna, in the press room, a cavernous hall appended to the U.N. complex, with lots of free strudel and little news of the talks. The real action was in Ukraine.

The Iran deal, dubbed the Joint Comprehensive Plan of Action, that eventually emerged in 2015 was unverifiable, stuffed with sunset clauses and secret side deals. It allowed Iran to carry on with what the Obama administration described as its “exclusively peaceful nuclear program.”

Instead of submitting it as a treaty to the Senate, President Obama rushed it to the United Nations Security Council, where his envoy voted to adopt it even though it was overwhelmingly opposed by our own Congress. Mr. Putin kept Crimea and the footholds in eastern Ukraine that he served up late last month as the pretext for invasion.

Mr. Biden and his aides are now reprising that playbook in cooperation with Russia and China for a revamped Iran deal that’s taking shape as even worse than the original. In Europe, Ukrainians are fighting Mr. Putin’s armed forces for their country and their lives. In Asia, China is sending relays of warplanes to threaten the Free Republic of China. It’s time for America to walk from the Iran talks.