President Biden, in his eagerness to renew a nuclear deal that would enrich Tehran, is reacting with shocking slowness and passively to growing Iranian death threats against Americans, as well as to the stabbing Friday of the author Salman Rushdie, critics say. 

Tehran’s non-denying denial of ties with the New Jersey man detained for stabbing Mr. Rushdie on Friday, Hadi Matar, was issued on a day that the Islamic Republic faces a deadline to answer a “final text” offered by a European diplomat last week. 

As of this writing, Iran has not responded to the American-backed European offer to renew the Joint Comprehensive Plan of Action. Proposed last week by the European Union’s negotiator, Josep Borrell, it was accompanied by a demand that Iran answer it today. 

Officials in Tehran said they would respond by midnight today, as Iran watchers say the answer is likely to be inconclusive and be designed to extend negotiations. Endorsed by the state department, Mr. Borrell’s offer reportedly included a compromise on demands made by the United Nations nuclear watchdog, the International Atomic Energy Agency.

In America, meanwhile, additional details emerged today about ties between Mr. Matar and the Islamic Republic’s Guard Corps, as well as Iran’s Mideast proxies. Mr. Matar’s mother, Silvana Fardos, told the Daily Mail that her son has changed and has been radicalized since a 2018 visit with his father in Lebanon.

The family hails from southern Lebanon, the stronghold of Hezbollah, a Shiite terror group that was founded by the Islamic Republic, which is its main financier and supplier of arms. After returning from that visit, Ms. Fardos said, Mr. Matar “was angry that I did not introduce him to Islam from a young age.”

Additionally, Mr. Matar’s Facebook page reportedly carried many references to Iran, including a photo of the Islamic Republic’s founder, Ayatollah Khomeini, who in 1989 issued a fatwa calling for the murder of the author of “The Satanic Verses.” The IRGC has offered a $3 million bounty for anyone who would kill Mr. Rushdie. 

“No one can blame the Islamic Republic of Iran” for the assault on Mr. Rushdie, the Iranian foreign ministry spokesman, Nasser Kanaani, said today. Yet, he tacitly endorsed the murder attempt by blaming its victim: “We don’t consider anyone deserving reproach, blame or even condemnation, except for Rushdie himself and his supporters.” 

Washington made its first reference to the Islamic Republic’s role in the attack only yesterday. “Iranian state institutions have incited violence against Rushdie for generations, and state-affiliated media recently gloated about the attempt on his life — this is despicable,” Secretary Blinken said in a statement. 

As of yet, though, President Biden has declined to punish Iran for the attack on Mr. Rushdie. Nor for as yet unsuccessful attempts against President Trump and officials of his administration, including a former national security adviser, John Bolton, former secretaries of defense and state, Mark Esper and Michael Pompeo, respectively, and the one-time point man on Iran, Brian Hook. Additionally, an American-Iranian dissident, Masih Alinejad, is in hiding after a second attempt on her life was foiled last month at Brooklyn. 

“Iran is actively plotting against multiple Americans,” the ranking Republican on the House foreign affairs committee, Michael McCall of Texas, said in a statement today, adding, “Waiting to impose consequences until after an attack is a dereliction of duty.”

Mr. Biden’s “priority needs to be protecting Americans, not negotiating a flawed nuclear deal,” Mr. McCall wrote, citing the latest reported proposal containing Western concessions. “Between these dangerous proposals and the mounting evidence of Iran’s terrorist activity on U.S. soil, l urge the administration to finally withdraw from talks and shift its focus to compelling Iran to stop its malign activities. American lives depend on it.”

Iranian officials acted as if an agreement on the JCPOA renewal was around the corner — as long as some of their latest demands were accepted. “We do not want to reach a deal that after 40 days, two months, or three months fails to be materialized on the ground,” Tehran’s foreign minister,  Hossein Amir-Abdollahian, said.

Calling on Washington to show “flexibility,” Mr. Amir-Abdollahian added, “We have told them that our red lines should be respected.”

Iran watchers say Tehran’s promised midnight answer might well be postponed by several hours, or more. Iranian diplomats have long employed delaying tactics, evidently preferring negotiations to completing a deal. Tehran’s reaction to Mr. Borrell’s latest concession is likely to extend that pattern. 

“Tehran may go for a ‘yes but’ or ‘no and’ approach, seeking clarifications, redefinitions, and more accommodations,” an Iran watcher at the Foundation for Defense of Democracies, Behnam Ben Taleblu, told the Sun. 

America and the Europeans, he added, have “no political appetite for a plan-B approach” that would replace Washington’s preferred diplomacy designed to renew the 2015 JCPOA. Tehran’s Mr. Amir-Abdollahian, on the other hand, said today that “like Washington, we have our own Plan B if the talks fail.”

That plan may already be in high gear and include plots to assassinate former officials and regime critics on American soil.