Your KiwiSaver balance:
Let's start with the most selfish reason to care about US/China relations right now.
Your KiwiSaver balance is likely to look a lot better at the end of the year if the meeting ends with any kind of conciliatory words or suggestion of compromise.
Stocks took a pummelling in October and November. The big driver is rising interest rates but markets are also worried about the escalating trade war.
US tech companies need access to Chinese consumers, production facilities and raw materials. They've been particularly vulnerable to speculation about where the trade stand-off is going next.
If the meeting goes well markets will likely rise on what would be described as a "relief rally". If it goes badly - expect some more fall-out.
It's a ridiculous binary way to view things - but that is markets for you.
The New Zealand economy:
In reality New Zealand hasn't been in the firing line of the first rounds of the trade war.
But the stand-off has cast a shadow over commodity markets and probably isn't helping dairy export prices - which have been sliding for a few months for a variety of reasons.
Basically a trade war has raised concerns about the outlook for global economic growth - which started the year pretty rosy.
China's economy is already under pressure. And though the US has been booming, the market slump and stories like GM closing a production plant and moving to Europe have sparked recession talk in the financial pages. The US Federal Reserve even responded by hinting it might pause on rate rises.
New Zealand's economy is solid but growth is expected to slow a bit in the next six month before picking up again. A global slump or crisis is never good but it would be really helpful if it didn't happen in the next couple of quarters.
World peace:
And at the risk of sounding like a beauty pageant contender - we all want a more peaceful world, right?
It would be hyperbole to say the stakes have never been higher. When John F Kennedy met Nikita Khrushchev in 1961 the world was staring down the barrel of nuclear annihilation.
But there are worrying signs that the US and China are heading towards a military stand-off in the Pacific and South China seas.
US Vice-President Mike Pence maintained a hard line at the Asean conference earlier this month and it ended in a stand-off between China and the US which sparked talk of a new cold war.
That's not good news for New Zealand which is economically dependent on China but culturally and politically aligned to the US.
As the pressure - from both sides - about allowing access to Chinese telco Huawei has proved this week, things get can get awkward really fast.
So which way will it go?
Let's not pretend it's possible to pick how Trump or Xi will play it. This US administration is very serious about standing up to China economically. It wants serious concessions and seems prepared to push on. The tariffs are only just starting to bite and will need time to have an effect.
The China regime won't want to back down either. Both sides have an historic eye on the balance of global power in the rest of the 21st Century.
On the other hand, from a pragmatic point of view, both may be prepared to offer short-term concessions.
China's economic growth is slowing already and it doesn't really need headwinds (in the form of tariffs) on its exports right now .
Also, ironically, a lot of the things the US wants China to do - strengthen its currency and increase imports - are things the Chinese also want to do.
At least, the Chinese regime knows it needs to do these things in the long term to rebalance its economy. So beyond the political posturing, the issue is really the pace of change not the direction.
If Trump can offer Xi a way to compromise and save face then there is some hope.
There are well sourced reports in the Wall Street Journal and from Bloomberg suggesting the US is working on just such a plan.
But (on the third hand) there is the wild card of Trump's personality. He seems to either bond extremely well or extremely badly in these meetings. There's not much middle ground.
Meanwhile you can expect Xi to maintain his poker face.
So it's complicated. But also fascinating. It's history unfolding.
