North Korean dictator Kim Jong Un and Donald Trump plan to meet in May for nuclear disarmament talks.
The whiplash development would put two leaders who have repeatedly insulted, threatened and dismissed each other in the same room, possibly in the North Korean capital of Pyongyang.
It would have been an unthinkable suggestion just a few months ago, when the insults were at their peak — Mr Trump was a “senile dotard” and Mr Kim was “Little Rocket Man”.
Meanwhile the North was firing off regular weapons tests in a dogged march toward its goal of a viable nuclear arsenal that can threaten the US mainland.
Liberal South Korean President Moon Jae-in, who some believe has manoeuvred the two leaders to this position, reflected the hope and relief many in South Korea feel about the planned summit.
He declared on Friday that it will be a “historical milestone” that will put the denuclearisation of the Korean Peninsula “really on track”.
But there is also considerable scepticism.
North Korea, after all, has made a habit of reaching out after raising fears during previous crises with offers of dialogue meant to win aid and concessions.
It has also, from the US point of view, repeatedly cheated on past nuclear deals.
And now the North has landed a face-to-face meeting with the leader of the world’s most powerful country, a nation that Pyongyang has long sought to draw into talks.
It hopes to establish a peace treaty to end the technically still-active Korean War and drive out all US troops from the Korean Peninsula, removing what the North says is a hostile encirclement of its territory by Washington and Seoul.
“Great progress being made,” Mr Trump tweeted after the South Korean national security director, Chung Eui-yong, emerged from a meeting with Mr Trump and announced the summit plans to reporters in a hastily-called appearance on a White House driveway.
That remains to be seen.
Some speculate that the North is trying to peel Washington away from its ally Seoul, weaken crippling sanctions, buy time for nuclear development and win aid by setting up a meeting with Mr Trump that will win it concessions.
North Korea still produces propaganda declaring its continuing dedication to the “treasured sword” of its nuclear program.
Washington still remains publicly dedicated to annual war games with the South that the North claims are invasion rehearsal.
They are expected to resume next month, after being postponed during the Winter Olympics in the South.
DC is also dedicated to keeping 28,500 troops in the South and 50,000 in Japan, largely as a way to deter North Korean aggression.
Talks between Washington and Pyongyang have previously been overseen by lower-level experts, and have often bogged down, even when so-called “breakthroughs” have come, in the pesky details, such as allowing outsiders in to inspect North Korea’s nuclear compliance, for instance.
Now, the talks will start at the top and there will be no time to settle all the problems that have scuttled previous negotiations.
It remains to be seen what Mr Trump and Mr Kim might decide in the highest-level meeting in what has been essentially a bloody, seven-decade standoff between their countries.