At the second UN General Assembly of Donald Trump's US presidency - and of António Guterres' tenure - the sense of novelty and apprehension that marked 2017 has given way to concern that revanchist forces are pushing back on human rights and in other areas.
Several leading participants this week in New York spoke of their disappointment that diplomacy and multilateralism are on the retreat, making it harder to disentangle some of the world's most intractable problems and conflicts - from Syria and Yemen to refugee resettlement and climate change.
And with the Trump administration running low on multilateral punching bags, relief officials and UN observers are now worried that the political weaponisation of aid might become the next frontier, with the US reducing vital funding for assistance programmes overseas that don't fit its agenda.
"US foreign assistance is not the president's personal charity."
"Moving forward, we are only going to give foreign aid to those who respect us and, frankly, are our friends," Trump threatened during his keynote speech at the General Assembly.
Many in his administration, including Defense Secretary James Mattis, are said to have limited appetite for pulling back too far on overseas assistance, and White House attempts to sharply reduce foreign aid overall have been repeatedly torpedoed by Congress.
However, the president's statement isn't complete bluster. In recent weeks a senior White House official has undertaken a review of foreign assistance. The aim is reportedly both the kind of quid pro quo arrangements described by Trump and an effort to neutralise China's growing "soft power".
Such moves have the sector worried that the world's largest aid donor by volume could be about to withhold assistance - or at least make sure there are more strings attached - just at a time when donor funds are failing to keep pace with soaring humanitarian needs.
"US foreign assistance is not the president's personal charity," Abby Maxman, president of Oxfam America, reacted in a statement following Trump's speech. "Such vindictive antics might be intended to score short-term political points, but they will cost dearly for the most vulnerable among us."
Trump's appearances this week, and their stark attacks on multilateralism, capped a year of building resignation about the limits of global partnership to solve humanitarian problems.
Over the past 12 months, President Bashar al-Assad's regime has - with Russia's help - all but decided the fate of Syria's seven-year war; anti-refugee politics have won over larger voting blocs in the West; the conflict in Yemen continues unabated; and Myanmar's military stands accused of perpetrating a genocidal campaign in full view of the UN.
"[Trump] seemed a bit listless in the General Assembly and he really did look notably isolated in the Security Council," Richard Gowan, a senior fellow at the United Nations University's Center for Policy Research, told IRIN. "So this adds to a sense of American drift at the UN."
US withdrawal has fed speculation - centred mostly on China's Xi Jinping - about who might attempt to fill the vacuum in global leadership, but going by the speeches at the UN General Assembly it looked as if countries were not so much moving in as moving on.
"It's not as if the Russians or the Chinese or any other powers have been actively doing things this week to undercut the US, but I think sort of by default they benefit from this perception of American isolation," said Gowan.
Some world leaders, including German Chancellor Angela Merkel and French President Emmanuel Macron, did use their UNGA platform to offer purposeful defenses of multilateralism, human rights, and sustainable development. But the gap left by the abnegation of US global leadership is yawning - wider still if the Trump administration actively works to spite cooperation among UN member states.
Human rights advocates in particular have been sounding the alarm about how easily hard-won gains could be unwound without protection. "Russia and China are trying to destroy human rights pillars, with the US enabling them across the board," Louis Charbonneau, the UN director of Human Rights Watch, told IRIN.
Of late, the United States appears to be running out of targets. It has already pulled out of UNESCO, cut funding for the United Nations Population Fund (UNFPA) over abortion rules, and left a global migration pact overseen by the UN.
In the run-up to the General Assembly, Trump's national security advisor John Bolton promised to undermine the International Criminal Court and sanction its judges. On what grounds that could take place is unclear, and in any event the US isn't a member of the court.
Arguably the most significant development came in June, when Secretary of State Mike Pompeo and UN ambassador Nikki Haley announced the US would leave the Human Rights Council.
Foreign aid hasn't been spared either.
The administration has hacked particularly viciously at humanitarian assistance for Palestinians. Last month it completely defunded the UN's agency for Palestinian refugees, UNRWA, and in September it zeroed out everything else, including $25 million in planned financing for the East Jerusalem Hospital Network.
And IRIN revealed in August how the Trump administration had put new limits on foreign assistance funded through the UN. A critical report published this week by USAID's inspector general may offer more ammunition to those in the administration who seek to cut or redirect UN funding.
Yet it's far from decided how damaging the administration's slashes and withdrawals will ultimately prove for the UN and the humanitarian aid it provides.
"There is obviously scepticism of whether multilateral action will deliver for US interests, and certainly USAID folks will be sensitive to that and aware of that," Tony Pipa, the former chief strategy officer at the agency, told IRIN.
"The larger policy conversation that Secretary of State Pompeo is going to be leading is likely to be looking at UN votes and what does that mean to providing budgets and assistance to countries themselves," he explained. "They are a little different, but they are both connected to a scepticism about the effectiveness of aid and specifically the effectiveness of aid going through multilateral organisations."
Other former officials said it was difficult to tell how serious the latest threats should be taken. "There's no order in the administration's foreign policy, so it's hard to know," said Dave Harden, a former USAID assistant administrator.
According to a report in the Washington Post, part of the White House plans consider using aid in a targeted battle with China, which in recent years has spread its largesse - and loans - across much of the developing world.
Though never immune from political considerations, development goals swapped for overtly political ones could render a significantly altered aid environment, aimed less at meeting urgency, and more susceptible to corruption as leaders battle to curry favour rather than demonstrate need.
"China and Western donors have a very different view of aid," said Gowan. "If the US redefines development as being purely a tool of national interest and very much in an effort to contest China's rise, then this idea of aid being a universal good is not guaranteed."
One didn't need to look far this week to see a similarly questionable dynamic playing out.
At a high-level humanitarian meeting on Yemen held Monday, speakers included the UN's relief chief Mark Lowcock and Lise Grande, the UN's humanitarian coordinator in the country. The crisis in Yemen, stated Grande, is the worst in the world, and worsening. "At least one child is dying every 10 minutes from causes linked to the war," she said.
Sat on either side of the humanitarian officials were the main donors to the UN's relief effort in Yemen; the closest being representatives from the UAE and Saudi Arabia. Both countries are principal belligerents in the three-and-a-half-year war and argue that their military intervention is defending the internationally recognised government. But their coalition is also responsible for thousands of deaths and mass displacement.
Critics of the Saudi Arabian-led intervention see the coalition playing such a large aid role as a contradiction, but Guterres has argued that a country's military actions and humanitarian commitments should be viewed separately.
"None of the work [the UN has] done... would have been possible without the generous support of the donors, and I'm proud that my country is on the top of the list along with our brothers the United Arab Emirates," Saudi ambassador Abdullah al-Mouallimi told the meeting in New York. "We must always remember that."