North Korea is a notoriously unpredictable nation and so it proved to be with the North Korean coach of one of Cambodia's most talented woman wrestlers, Chov Sotheara.

After a series of complex negotiations, missed appointments and a tropical deluge, we finally got to meet the man who's been coaching Sotheara for greatness.

But not for long.

Pak So-nam shook our hands firmly, looked us straight in the eye, and disappeared.

Pak might not have had much time for us, but he has plenty of time for Cambodia. He's been coaching the country's best wrestlers for six years and is assisted by two of his compatriots. None of them seemed to have minders and looked to be left to their own devices.

It's a reflection of the unusually cordial, and deep-seated relationship between the two countries a friendship Cambodia now hopes it can use to encourage the North back to the nuclear negotiating table and burnish its own diplomatic credentials as host of this week's ASEAN Regional Forum.

It all started back in the Cold War era with Cambodia's then-king, Norodom Sihanouk, the man who took power at the age of 18 and led the country to independence from the French.

Exiled in the early 70s and then forced out by the Khmer Rouge – a group he'd earlier helped bring to power - the King found a perhaps rather unlikely friend in North Korean founder Kim Il-sung.

Newsreels from the time show Sihanouk and his wife meeting Kim in front of hundreds of thousands of cheering North Koreans. In the manner of such propaganda material, the women are beautiful, happy and carrying bouquets of red flowers. The men are in uniform - perfectly drilled and serious in intent.  Kim is waiting for Sihanouk as his train arrives, greeting his friend with a bearish hug and a fraternal kiss.

Sihanouk wrote a paean to Kim. And even in death, the North's "Eternal President" called Sihanouk his brother. The two shared a love of the movies, culture and the arts.

Photographs from the Royal Palace archive underline the depth of their friendship. In a photograph taken in 1973, the Cambodian royal family, including the current King, pose with Kim Il-sung in the lush grounds of his villa.

Another, from 1981, shows Sihanouk and his entourage strolling in outside the North Korean home Kim Il-sung built for him south of Pyongyang. A 2006 photo shows Sihanouk framing a shot for one of the scores of films he made during his extended periods in the country. 

That was the last time Sihanouk, now known as the King Father, visited Pyongyang. He now spends most of his time in Beijing where he's being treated for cancer.

Nevertheless, Cambodia's friendship with North Korea appears to have endured.

The North Korean embassy sits on a prime spot of real estate right next to the grandiose home of Cambodia's Prime Minister Hun Sen. A Phnom Penh street is named after Kim Il-sung and in April, officials from the city, joined North Korean diplomats to unveil a monument marking the centenary of Kim's birth. It might be marooned on a rather dusty traffic island in one of the capital's less fancy locales but the sentiment is there.

Cambodia is also home to two of the North's official "Pyongyang" restaurants: one in Phnom Penh and the other in the tourist mecca of Siem Reap. The all-singing, all-dancing dining experience, where the menu is in US dollars, provides much needed foreign exchange for a country squeezed by international sanctions.

For sure, there have been hiccups – in 2006, it was revealed that North Korean defectors had been escaping to the South through a secret pipeline to the West – and Hun Sen, himself a wily politician, has shown a certain pragmatism in his dealings with the country.

The personal connection that is at the root of the diplomatic relationship may have cooled with Kim's death and Sihanouk's illness, but it's still reflected on the streets of Phnom Penh. As in so much of Cambodia, the past continues to reverberate in the present.