Bill Richardson, a former US presidential candidate and currently governor of out-of-the-way New Mexico, grabbed world headlines over the weekend.
He travelled to North Korea and, amid heightened tensions on the Korean peninsula, announced a wide-ranging deal with Kim Jong-il's regime.
At Mr Richardson's persistent urging, the North said it would not retaliate against South Korea for conducting live-fire artillery drills on Monday.
Earlier, it had threatened global nuclear war if Seoul decided to go forward with them.
During the drama, US Secretary of State Hillary Clinton and President Barack Obama's special North Korea envoy Stephen Bosworth were nowhere to be seen.
Also invisible was Washington's Ambassador to Seoul, Kathleen Stephens. In short, America's diplomats melted into the background as a "freelancer" took centre stage.
Mr Richardson, sometimes called America's ambassador to rogue states, perhaps helped to avert a serious conflict. On the other hand he may have set in motion another decade of fruitless diplomacy.
What we know for sure is that he is having an outsized impact on developments.
Mr Richardson went to Pyongyang at the invitation of Kim Kye-gwan, the country's chief nuclear negotiator.
The trip, according to the US state department, was "a private visit", and the governor did not carry any official messages from Washington.
Mr Richardson's visit genuinely seems to be the result of Pyongyang's initiative.
"When they call me they always want to send a message of some kind," the New Mexico governor said recently.
As such, Mr Richardson's trip highlighted the existence of back channels connecting the US to regimes with which it is at odds.
Mr Richardson, whose bags are always packed for trips to such countries, seems particularly effective when it comes to getting things done in North Korea.
In 1994 and again in 1996 he secured the release of US hostages in North Korea.
But Mr Richardson is not the only unofficial hostage negotiator for the Korean peninsula.
Last year, former US President Bill Clinton, as a private citizen, brought back two television journalists from North Korea after the state department worked out the terms of their release.
Mr Clinton wisely stuck to the guidelines Washington gave him and largely avoided becoming entangled in nuclear negotiations.
Not so Jimmy Carter, who brought back jailed English-language teacher Aijalon Gomes from Pyongyang this August.
The 39th US president lobbied hard for the opportunity to free Mr Gomes and had to fight off Senator John Kerry, who represents the Boston resident, for the honour.
The North Koreans in the end insisted on Carter, presumably because he had been so useful nearly two decades earlier.
In 1994, the world appeared to be on the brink of a war involving North Korea.
Bill Clinton, the then-US President, had stitched together an international consensus for tougher measures against Pyongyang over its nuclear programme.
Because the North was saying that sanctions meant war, the US began preparing for just that.
It is unlikely that North Korea's then-leader Kim Il-sung was willing to start a conflict with a vastly superior US and South Korea - we will never know because at that moment in walked Jimmy Carter, who had told Mr Clinton he was going to Pyongyang to meet Mr Kim.
Mr Carter's attempts to travel to the North Korean capital in 1991, 1992, and 1993 had been rebuffed by the state department, but he absolutely insisted on going at the height of the crisis in 1994.
In talks with Mr Kim that June, he worked out a tentative deal.
Then to make sure that his personal diplomacy would not be undone, Mr Carter, while still in the North Korean capital, gave a now-famous live television interview.
He termed his work in Pyongyang "a miracle".
But the deal he suggested, which later became the Agreed Framework, gave North Korea the time and resources to covertly build its nuclear weapons and openly test long-range missiles.
Moreover, the deal signalled America's acceptance of the regime and, in all probability, saved it from collapse during an especially vulnerable period of transition from Kim Il-sung to his son, Kim Jong-il.
Personal, freelance diplomacy averted one crisis in 1994 only, some say, to create another in 2010.
Whether Bill Richardson ends up finding an enduring solution now, during another leadership transition in Pyongyang, will be the ultimate test of America's informal approach to crisis resolution.
Gordon G. Chang is a Forbes.com columnist. Follow him on Twitter @GordonGChang