From within the confines of the General Assembly, it might have seemed, for much of this week, as if the United Nations was experiencing some sort of a 70th-birthday reboot.
Seven decades after the end of the Second World War spurred the UN's birth, the leaders of the world's major powers struck a surprisingly new tone in their traditional annual addresses to the 193-nation body – if you didn't listen too closely to the details.
Almost every country's leader, from the United States to China to Iran and even Russia, spoke of the importance of multilateralism, of shared international causes, of the end of superpower dominance of the world system, of common priorities. Countries that had previously used the forum to rant against the international system, notably Iran and China, instead spoke in support of it.
The UN, Chinese President Xi Jinping declared, has "reached a new historical starting point." Seventy years after what he called the "People's war of resistance against Japanese aggression and the world anti-fascist war," he called on the member states to create "a new type of international relations featuring win-win co-operation and … a community of shared future for mankind."
To back this up, China – which until recently tended to largely ignore the UN and abstain from its Security Council votes – announced some profound new commitments to the organization: a $1-billion (U.S.) fund to support the UN's international development work over the next decade, $100-million in military assistance to the African Union and, very significantly, China's entry into the blue-helmet peacekeeping system with a huge contribution of 8,000 troops. (By comparison, Canada currently has fewer than 50 peacekeeping troops, and had a peak of around 3,000.)
This new spirit of multilateralism extended, at least rhetorically, across the week: Iranian President Hassan Rouhani declared that "today, a new chapter has started in Iran's relations with the world," and he used this year's completion of a nuclear arms-control deal and the end of sanctions against Iran as an opportunity to call for a "united front" against extremism and terrorism.
The disparate leaders even seemed to agree on a common military goal: Almost everyone said they wanted to use military means, and a global alliance, to defeat the terrorist army known as the Islamic State, or ISIS.
"On the basis of international law, we must join efforts to address the problems that all of us are facing and create a genuinely broad international coalition against terrorism," Russian President Vladimir Putin declared. U.S. President Barack Obama echoed: "The United States is prepared to work with any nation, including Russia and Iran, to resolve the conflict."
But it was here that the apparent spirit of internationalism began to fray at the edges. For in declaring their interest in a UN-focused, global co-operation to solve problems – both in Syria and more widely – the leaders were talking about very different, and often completely opposite, things.
Mr. Putin, whose invasion of Ukraine has put him at odds with much of the UN for having impinged on a member state's sovereignty, was talking about using military action to keep Syrian dictator Bashar al-Assad in power, and denouncing those who would threaten Mr. al-Assad's sovereignty.
"We should finally acknowledge that no one but [Mr. al-Assad's] armed forces and the Kurdish militias are truly fighting the Islamic State and other terrorist organizations in Syria," Mr. Putin declared. "The only way to solve this problem at a fundamental level," he said, "is to restore their statehood where it has been destroyed, to strengthen the government institutions where they still exist or are being re-established and provide comprehensive assistance to the legitimate government of Syria."
He backed up those words with a major bombing campaign that began almost as he was delivering that address.
Mr. Obama and his allies, on the other hand, insisted that no peace could come without Mr. al-Assad's departure.
"Assad is the origin of this problem, and cannot be part of the solution," French President François Hollande declared. Mr. Obama called for a "managed transition away from Assad and to a new leader, and an inclusive government."
And indeed, on Friday the leaders of the United States, Britain, France, Germany, Qatar, Saudia Arabia and Turkey issued a joint statement calling on Mr. Putin to end his attacks on the Syrian anti-Assad opposition.
So much for the united front on Syria. But beyond passive-aggressive sparring over this crucial issue, much of the rhetoric of international co-operation was but a thin veneer covering some deep divides over the meaning of those words.
Mr. Xi, for instance, devoted much of his speech to the traditional Chinese Communist argument that international values and a liberal order do not really exist – that, in the words of the British China scholar Shaun Breslin, the values articulated at the UN "are not universal at all, but merely the product of a small number of Western countries' histories, philosophies and developmental trajectories."
Likewise, Mr. Putin's speech was largely devoted to denouncing democracy and anti-dictatorship movements in the Middle East, Ukraine and elsewhere as concoctions of dark Western forces manipulated by the United States.
"We consider attempts to undermine the legitimacy of the United Nations as extremely dangerous," the Russian President said. They were words which every other leader would, on the face, agree with – but for the fact that, as this week's events showed, nobody agrees whether people like Mr. Putin are opposing those legitimacy-undermining forces, or if they are the embodiment of them.