Why Biden’s Pick for Iran Envoy Is ‘a Proxy for Everything’

But Mr. Malley, the son of a Jewish Arab leftist, is a well-known advocate for engaging with groups and governments — including, over the years, Hamas, Hezbollah and President Bashar al-Assad of Syria — widely considered enemies of the United States and Israel and, by some, morally off limits for contact. To his critics, he is overly suspicious of American power and overly sympathetic to foreign actors including Iran and the Palestinians who have deep disputes with the West.

As Mr. Biden’s point man for Iran, responsible for reining in its expanding nuclear program, those critics fear, Mr. Malley will press for a new deal with Tehran that will concede too much to its clerical rulers in the name of reconciliation. When word of his appointment first appeared in the news media, Senator Tom Cotton, Republican of Arkansas, condemned “radicals like Malley” who, he said, holds “a long track record of sympathy for the Iranian regime” and “animus towards Israel.”

Other opponents of negotiating with Iran expressed concern in more temperate terms. “The appointment of Rob Malley may be a clear indication that the Biden administration is prioritizing a return to the J.C.P.O.A. over a policy of deploying American power to get a more compressive and permanent agreement,” said Mark Dubowitz, the chief executive of the Foundation for Defense of Democracies, referring to the 2015 nuclear deal, known as the Joint Comprehensive Plan of Action, which he has long opposed. “Malley is not a believer in American power,” he added.

Defenders of Mr. Malley, whose position does not require Senate confirmation, say that he has become a convenient target for an opening salvo from the American and Israeli right intended to warn the Biden administration against trying too hard to work with Tehran on another nuclear deal like the 2015 agreement that became one of the most bitter foreign policy battles of the Obama years.

“Most of the judging of Rob comes from people who do not know him and who choose to believe that he has no conception of American national interests, and that it’s all about trying to find a way at any costs to reconcile with our enemies,” said Aaron David Miller, a Middle East peace negotiator under multiple presidents who worked with and is close to Mr. Malley.