Can China and the US heal ties as Xi Jinping meets Joe Biden in San Francisco?
President Biden likes to wax lyrical about the many days he has spent in Xi Jinping's company, including his memory of a moment they shared on the Tibetan plateau when he was asked by the Chinese leader to sum up America in one word.
Mr Biden apparently responded with "possibilities".
The American president's recollections of the amount of time they have shared together are somewhat exaggerated - they've spent hours not days - and by all accounts they were never on the Tibetan plateau.
But the two men do go back a long way, knowing each other before the both became leaders. In the past they have appeared to have a good rapport, but not of course on the level President Xi shares with his "no limits" friend Vladimir Putin.
Their meeting in San Francisco is about halting a downward spiral in relations between the world's two most powerful economies.
A flurry of diplomatic visits in the preceding five months between officials from each side has already arrested the freefall triggered by the so-called "spy balloon" incident in February this year. The groundwork has been done for the leaders to officially sit down "eyeball to eyeball" and agree to stabilise relations and "dial down" the rhetoric.
On Wednesday morning, before the two leaders had even met, an announcement was made that the two countries have already done a deal promising to increase their transition to renewable energy sources.
The details on that had been thrashed out by the US Climate Envoy John Kerry and his Chinese counterpart Xie Zhenhua who met in California before the leaders arrived. It doesn't include any specifics on China reducing its dependency on coal, but it shows a willingness to work together on climate change, one of the most pressing issues facing the planet.
Deals are expected to be made on AI safety, on Fentanyl, specifically a pledge from China to crack down on the suppliers of the chemical precursors to the synthetic opioid, and there are expected to be agreements on the resumption of military to military communications which were halted last summer following the visit of then House Speaker Nancy Pelosi to Taiwan.
The bar is low for anything of great substance, and it will take more than a four-hour meeting on the sidelines of a summit to build any significant trust between the two sides. There must be sustained high-level contact, and regular meetings between the two leaders.
But it is a good thing for the world that the US and China are at least still on speaking terms, you just need to look at what is going on in the world right not to recognise the importance of that.
President Biden and President Xi will look directly at one another, but their viewpoints are completely different. Their ideologies and their world views are opposing.
When he took office Mr Biden framed their competition as autocracy vs democracy. That has stuck with the Chinese Communist Party as an unhelpful, even threatening framing.
The US stands with Ukraine, while China supports Russia, in the latest conflict the American administration has given its backing to Israel, while Beijing is tacitly pro Hamas.
You just need to look at who President Xi has hosted this year – the Iranian President, the leader of the Palestinian Authority, the Syrian President, the Taliban, and of course, guest of honour at the recent Belt and Road Forum was President Putin.
It gives you a pretty good idea of who President Xi has in mind when he's talking about a shift in global order.
Before this summit I was reminded of a quote from the Singaporean Foreign Minister who said when it comes to US-China relations "the weather may have changed, but the climate remains the same".
And former Chinese President Deng Xiaoping once remarked that US-China relationship would neither be exceedingly good nor disastrously bad. That remark from President Deng still rings true but China has grown and changed a huge deal since he made that observation.
The two countries are more interdependent that ever, and perhaps more than they would both like to admit, but in recent years, and even in recent weeks competition between the Western and Eastern powerhouses has risked developing into confrontation.
The rest of the Asia Pacific nations gathered in California for the APEC meeting will be looking for sincere signs of cooperation, that will keep conflict from their shores.
Want a quick and expert briefing on the biggest news stories? Listen to our latest podcasts to find out What You Need To Know