Choosing the location for these big meetings is often just as much of a headache.
In some cases it’s fairly straightforward, particularly when you’re talking about member countries simply rotating the hosting duties for groups like the G20, APEC and ASEAN and CHOGM (acronyms are big on the international conference circuit).
But the Donald Trump-Kim Jong-un summit is a much more sensitive proposition.
Singapore was chosen as the venue for their first meeting in June last year, because it was one of the few countries to have diplomatic relations with both the US and North Korea.
So, why did Vietnam emerge from the pack as the host country for the second get-together?
North Korea and Vietnam have a few big things in common.
They are, of course, two of the world’s last remaining communist regimes. Cuba could have been chosen, but that was probably too close to the US mainland for Mr Kim’s liking.
Vietnam helps North Korea with training and technology in areas like manufacturing and farming.
The two countries also have the shared experience of fighting bitter wars against America, but it’s what they each did afterwards that sets the countries apart.
North Korea has remained isolated from the rest of the world; a rogue state run by a brutal family dictatorship with many of its people living in abject poverty. Mass starvation is the norm.
Vietnam, on the other hand, took a markedly different post-war path.
After struggling in the immediate aftermath of the fall of Saigon, the country embarked on sweeping reforms in the mid ’80s that have now produced one of the fastest growing economies in the Asia-Pacific region.
‘One day, this could be yours’
It is this hybrid model of one-party rule and a vibrant economy that the US and South Korea hope will prove very attractive to Mr Kim.
Sure, the model of Vietnam’s communist regime is quite different to North Korea’s.
Hanoi has a collective leadership whereas in Pyongyang, it’s all about the Cult of (Mr Kim’s) Personality.
But after a few days in the bustling Vietnamese capital, Mr Kim may realise that an eventual de-nuclearisation deal, coupled with the opening up of the North Korean economy may help ensure his long-term survival.
Huong Le Thu, a senior analyst at the Australian Strategic Policy Institute, says the North Korean leader is already showing positive signs on this front.
“I do think there are some factors that show he is really paying more attention to economic development than his father and grandfather,” she said.
“In recent years there has been a certain shift in North Korean policy, not only focusing on the military, or military first, but increasingly talking about a good culture, or production factories or shifting to include economic development in national strategy.”
So what’s in it for Vietnam?
For Vietnam, this week represents a golden opportunity to burnish its international credentials.
Nearly 45 years after the end of the war, Vietnam is now one of America’s strongest allies in the Asia-Pacific, and hosting the summit will help underscore its growing influence in the region.
The country shares America’s (and Australia’s) concerns about China’s activities in the South China Sea, a body of water that laps onto Vietnam’s coastline.
Even though its human rights record is far from perfect, Vietnam has robust global ambitions, and is angling for a non-permanent seat on the United Nations Security Council for 2020/21.
Dr Huong Le Thu said while it was unlikely there would be a big de-nuclearisation deal in Hanoi, just playing host to the summit was a huge coup for Vietnam. Even more so if Donald Trump and Kim Jong-un use the opportunity to declare the formal end of the Korean War.
“If there was some sort of peace treaty or peace declaration with a Hanoi name on it, that would probably be ideal for the hosts,” she said.
But there’s even more to it.
Having successfully hosted the 2017 APEC leaders’ conference, Vietnam is hoping a successful Trump-Kim summit will send more big international meetings its way.
And with the eyes of the world on Hanoi, all those (free) images of beautiful tree-lined boulevards, ancient temples and serene lakes will be a tourism marketer’s dream.
What’s in it for Australia?
Not being a target of a North Korean intercontinental ballistic missile armed with a nuclear warhead would be a VERY big start (if there’s substantial progress towards a nuclear-free Korean peninsula).
The Pyongyang regime has successfully tested a couple of these missiles, but the international jury is out on their nuclear capabilities.
A successful summit, continuing the gradual detente between North Korea and the US, would only be a good thing for the region, with tensions already high care of China’s growing assertiveness.
A rise in Vietnam’s international status would help bolster Australia’s strategic and economic relationship with this key Asian neighbour.
Vietnam is already Australia’s fastest growing trading partner in the ASEAN region, and leaders from both countries are keen to see these ties strengthen even further.
A private train owned by Mr Kim has rolled into Vietnam ahead of the first meeting between the leaders on Wednesday evening, and Mr Trump arrived late on Tuesday local time.
It’s going to be a big moment in Hanoi in more ways than one.