Image copyright Ed Jones/Getty Image caption Protesters in Seoul called for peace talks between the US and North Korea in November

They were called the "peace Olympics", but let me tell you, there was no peace in Pyeongchang.

There was a constant cacophony from the crowds inside and outside the stadiums. An atmosphere of excitement and wonder at what medals could be won.

In contrast, the huge diplomatic efforts surrounding the Winter Games are discussed in uncertain whispers.

Did you see North Korean President Kim Jong-un's sister? Do you think the South Korean president will go to Pyongyang? What could happen next?

South Koreans have endured over 60 years of dramatic ups and downs with the North and have learned to speak quietly about any hopes of a breakthrough.

But there now appears to be a small window of opportunity - the first in many years. But it may not last long.

North Korea is sitting down regularly with the South, and did not walk away when the subject of nuclear weapons arose. The South Korean Unification Minister, Cho Myoung-gyon, made that clear to me.

"We did convey the message to North Korea multiple times that in order to improve relations between the two countries we need to see a denuclearisation of the peninsula," he said. "It is necessary that North Korea talk to the United States to solve this in a peaceful manner."

North Korea has also announced it is willing to talk to the US.

But what does America want to do?

"We want to talk," US President Donald Trump said on Monday, but then he added: "only under the right conditions." He failed to specify what those conditions were.

Then, just hours later came a potential problem. Joseph Yun, one of the US state department's most experienced diplomats on North Korea announced his decision to retire.

He told reporters that "the time was right" and denied that it had anything to do with differences on White House policy. Analysts believe Joseph Yun was very much in favour of compromise and diplomacy.

His departure could handicap the Trump administration's progress with North Korea just as Pyongyang has made the rare decision to take part in talks.

Image copyright Toru Yamanaka/Getty Image caption Joseph Yun leaves his post as a US special representative for North Korea policy without a successor

Professor John Delury from Yonsei University in Seoul said this was a bad sign.

"Why is he retiring without a replacement? Any self-respecting CEO would not allow a key member of staff to resign without announcing their replacement. It's standard business practice."

Building even the crudest relationship with North Korea is difficult and will take expert handling. And right now, the Trump administration has failed to nominate a US ambassador to South Korea, let alone a point man on North Korea.

Prof Delury added: "There are no resources for basic diplomacy. The Trump administration has said North Korea is its top national security priority and yet they are not staffing it.

"You can't rely on maximum pressure alone. You can continue to squeeze them and pressure has a place but you have to combine it with talking to them, and this is at least a chance to start."

White House spokeswoman Sarah Sanders has tried to clarify the US position.

"Let us be completely clear," she said. "Denuclearisation must be the result of any dialogue with North Korea. Until then, the United States and the world must continue to make it known that North Korea's nuclear and missile programmes are a dead end."

While the US appears to lack the staff, South Korean President Moon Jae-in appears to be doing most of the work.

President Moon campaigned on a promise to engage with North Korea and seized on the opportunity offered by President Kim Jong-un during his New Year's speech.

His approval ratings have bounced back after his decision to integrate ice hockey players from the North into the national women's team. In fact, there were tears at the airport when the two sides said goodbye.

Image copyright EPA Image caption Strong attachments were formed during the Winter Olympics

But now President Moon is battling the clock and has asked the US to lower the bar for talks with North Korea. He seems eager to try to get some progress before joint military exercises are due to resume after the end of the Paralympic Games. These inflame Pyongyang, and have often prompted missile tests in response.

If real progress is to be made, he needs the US and North Korea to sit down before then.

Professor Kim Jang-ho from Hankuk University believes that for this reason, the detente won't last. He is also sceptical of President Moon's motives and doesn't believe there has been any breakthrough with North Korea.

"President Moon is trying to buy some time so that he can achieve a summit meeting with Kim Jong-un.

"Our president wants to meet him to symbolically say that North Korea is a normal nation and they are capable of talking. It automatically propels him to the list for the Nobel Peace Prize. But the US and Japan will pressure us to go ahead with military exercises as soon as possible, late April maybe.

"I think certainly with those exercises continuing, and they will go ahead definitely before May, we will go from the thaw to tension all over again."

Many doubt North Korea's willingness to discuss getting rid of its nuclear weapons with the US. Kim Jong-un has tried to reassure Seoul by saying his missiles are not pointing at South Koreans, they're pointing instead at the "US aggressors", and that they could be used to protect all of Korea.

I put it to Professor Bong Young-shik that North Korea would never give up its missiles. The research fellow at Yonsei University disagreed.

"The North Korean regime's ultimate goal is survival and security," the expert in North Korea said.

Image copyright Reuters Image caption North Korea says its long-range missiles protect all of Korea from "US aggressors"

"If having nuclear weapons and intercontinental ballistic missiles don't guarantee the survival of the regime and in fact, eventually threaten the very goal of the regime, then the regime will abandon its nuclear weapons and missiles. That is the whole point of the maximum-pressure strategy employed by the Trump administration."

However, he adds this rather important caveat:

"The maximum pressure imposed by the US may also compel North Korea to use those weapons as a last resort for survival, so it is kind of a high-risk, high-stake poker game between Washington and Pyongyang."

South Korea is at the centre of this poker game which is now at a critical moment. President Moon has taken things as far as he can without other key players getting involved. It is time for the US to show its hand.