Nearly six years ago, the Obama administration pulled off one of the most impressive diplomatic feats in a generation: it negotiated a seven-nation nuclear agreement with Iran. Just as importantly, the policy — formally known as the Joint Comprehensive Plan of Action (JCPOA) — worked exactly as planned once it was implemented.

Nevertheless, Donald Trump abandoned the policy for reasons he struggled to explain. The Republican insisted a new, “maximum pressure” campaign would force officials in Tehran to return to the negotiating table and accept a deal even more favorable to the United States, but that approach failed spectacularly: Iran ignored overtures, accelerated its nuclear program, and became vastly more dangerous as a result of Trump’s approach.

President Joe Biden has the unenviable task of trying to put things right. That process is now beginning in earnest with a new U.S. special envoy on Iran — who happens to be one of the officials who helped negotiate the landmark 2015 nuclear agreement. NBC News reported this morning:

According to a State Department official, Secretary of State Antony Blinken has chosen Robert Malley the White House Coordinator for the Middle East, North Africa and the Gulf region under former President Barack Obama, to be the Biden team’s point person on Iran, expected to be a critical foreign policy issue for the administration.

Malley “brings to the position a track record of success negotiating constraints on Iran’s nuclear program,” the official told NBC News. “The Secretary is confident he and his team will be able to do that once again.”

It’s no secret that Biden hopes to restore the policy that was working before Trump withdrew from the international accord. It also stands to reason that choosing Malley to serve as the administration’s envoy is intended to move toward that goal.

But the process won’t be short. As the New York Times explained:

Mr. Malley will be responsible for trying to persuade Tehran to rein in its nuclear program — and stop enriching uranium beyond limits imposed by a 2015 deal with world powers — and agree to new negotiations before the United States lifts its bruising economic sanctions against Iran. It is far from clear if the strategy, as directed by Mr. Biden, will succeed. Iran has repeatedly said it will not come back into compliance with the 2015 nuclear accord until the United States eases its sanctions, setting up a high-stakes contest over which side will blink first.

While the diplomatic work is bound to take a while, time is of the essence: with the United States having withdrawn from the international agreement, Iran doesn’t feel bound by its restrictions. NBC News’ report added this morning that officials in Tehran yesterday said the country was producing uranium enriched to 20 percent, “moving its nuclear program closer to weapons-grade enrichment levels.”