In coming days, presidents and prime ministers from an estimated 130 countries will come together in New York.
But during this time there will be only one meeting that could determine the immediate fate of the world: that will be in Washington between US President Donald Trump and Chinese President Xi Jinping.
For the leaders gathering in New York at the United Nations General Assembly, there are of course major issues to be discussed: a suddenly expressed panic over artificial intelligence (AI), the Iran war and its resulting crisis in the world energy market, erratic immigration flows and climate change being among them.
On the Iran war, the reality is that Trump is unable to end it. It takes two to end a war, and at this moment the Islamic Revolutionary Guard Corps (IRGC) which runs Iran does not want the conflict to end.
The IRGC wants to inflict as much political punishment as possible on Trump for what they believe have been unjustified attacks on their infrastructure and civilians. These attacks include the suspected US strikes on an Iranian school that killed 120 school children, an attack which the UN last week determined could amount to a war crime.
Iran's President Masoud Pezeshkian will address the UN on the home turf of the country it remains at war with, while at the same time, the US has blocked Palestinian leader Mahmoud Abbas from attending the same summit designed to be a global gathering to promote international peace.
This alone is extraordinary, the United States is allowing the leader of a country with which it is at war to enter New York while preventing the leader of the moderate faction of the Palestinians from attending, for the second consecutive year.
Abbas's Palestinian Authority is a bitter opponent of Hamas, and for years American officials have wanted the moderates to be embraced as part of trying to find a way towards a two-state solution.
But now not even a moderate Palestinian leader is allowed into the US.
China challenging the supremacy of the US
As is increasingly the case in this new world order, China is likely to prove yet again to be a key player.
It was China who brought together Iran and Saudi Arabia in Beijing three years ago to encourage them to drop the ancient Shia-Sunni rivalry, so it is China who could mediate between the US and Iran. But only if it so chooses.
So far, China's economy has not been badly impacted by the Iran war as it has enormous oil and petrol reserves.
But should the war drag into next year, as many in Washington expect it might, then China will have a real reason to pressure Iran to end the war because by then, its own oil reserves will start to diminish. China has a much greater ability to bring an end to this war than the US.
That is yet another indication that China is challenging the supremacy of the US in international matters.
China has tended to be reluctant to get involved in international conflicts but when self interest is involved, it reconsiders.
When the UN General Assembly met last year, the world was a very different place. Since then, the BRICS trade alliance — consisting of Brazil, Russia, India, China and South Africa — has become much stronger.
Xi told the BRICS meeting in New Delhi recently: "China is willing to work with fellow BRICS members to play a role in achieving peace and stability in the Middle East and the Gulf region."
And separately, South Korea, Japan and China have begun discussing a new trade pact.
China is skipping UNGA this year, with Xi heading directly to Washington to meet with Trump.
A year of change in the US and abroad
Another major change since last year is that Iran has managed to close the Strait of Hormuz, affecting 20 per cent of the world's energy flows.
In addition, the Iran-allied Houthis in Yemen have shown they, too, can jeopardise the flow of oil through the Red Sea.
And since last year, traditional US allies Saudi Arabia and Canada have had a rude awakening.
In the past fortnight, Trump reportedly twice has rejected Saudi requests for military assistance against the Houthis. In effect, he told Saudi Arabia that when it comes to their military battle against the Houthis they are on largely on their own, with the exception of some shared intelligence.
And in terms of Canada, historically one of America's closest allies, in recent weeks Trump has declared a full-scale trade war against a country which is the major trading partner for 25 American states.
In another shift since last year, the attitudes of many countries, including the US, have hardened against Israel. While the White House continues to support Israel, the attitudes of the American public have turned.
Surveys by both the Pew Research Centre and Gallop show there is now more support in the US for Palestinians than there is for Israelis.
Added to this, US Vice-President JD Vance has recently warned the US is the "only powerful ally" Israel has left in the world.
Europe warned 'no-one is safe' from Russia
In terms of Europe, since last year European countries have begun examining the possibility of a NATO alliance without the US.
Countries such as Poland are also now on heightened alert for a military attack by Russia.
French President Emmanuel Macron warned recently of the risk of Russian hybrid warfare in Europe.
"The nature of Russian aggression and threats in Europe is changing," the president said during a security briefing last Friday. "No-one is safe."
The "Russian hybrid threat against Europeans and France has intensified", he added.
And finally, a war that Trump once said he could solve within 24 hours, Ukraine, is worsening.
French media is reporting that in a single night late last week, there were as many as 138 drone or cyber attacks by Russia on neighbouring countries other than Ukraine, including Estonia and Poland.
All of these crises rage while conflicts in Gaza, Sudan, Myanmar and the Congo continue, raising the question of the UN's efficacy to end global conflicts.
So while leaders from 130 countries grapple with all of these changes, in Washington, Trump and Xi will sit down. If they were able to come to an agreement, these two could address key issues such as AI and the Iran and Ukraine wars.
But given the fierce competition between the two, few people are expecting that to be the case.
