Guterres' alacrity was a sobering way to open the annual United Nations General Assembly (UNGA) on Tuesday. But in the face of COVID, climate change, rising authoritarianism, human-rights abuses, disinformation, income inequality, nuclear proliferation and other problems crossing countries and continents, it was an accurate assessment.

President Joe Biden, making his first UNGA address, picked up on many of these themes and rightly suggested that the transnational challenges couldn't be tackled by one nation alone. In an intentional inversion of former President Donald Trump's "America First" focus, Biden embraced the U.N.'s ethos.

"To deliver for our own people, we must also engage deeply with the rest of the world," Biden told the assembled delegates. "We're opening a new era of relentless diplomacy, of using the power of our development aid to invest in new ways of lifting people up around the world."

Lately, however, some of Biden's actions haven't been perceived as relentless but instead have spurred resentment.

The administration's shambolic withdrawal from Afghanistan stranded Afghan allies (and some Americans), and a mistaken drone strike on an Afghan family expanded the tragedy. Reportedly, many NATO nations that had answered America's Article 5 call for collective defense weren't consulted on the abandonment, and some who were opposed it. But the president proceeded anyway, alienating allies and belying the belief that his traditional transatlantic viewpoint would revitalize strained U.S.-European relations.

Strained is a mild description of how France feels about a recent nuclear-powered submarine deal between the U.S., the United Kingdom and Australia. The newfound alliance — called AUKUS — was more than awkward for Paris, which had a deal with Canberra to supply Australia with French subs. It's a "stab in the back," the French foreign minister said as his nation recalled its ambassador to the United States.

The sub deal is meant to counter a rising China, even as the president proclaimed at the U.N. that the U.S. is "not seeking a new Cold War or a world divided into rigid blocs."

But the reality is that to respond to the China challenge diplomatically instead of militarily ("U.S. military power must be our tool of last resort, not our first," Biden told the UNGA), Western and Pacific alliances are essential. Infuriating France, America's original ally, is an unforced error that a president with nearly 50 years of Washington experience should have been able to avoid.

These fissures with friends, let alone the enduring tensions with adversaries, will make it harder for the U.S. to lead on the crucial, even existential, questions of ending the pandemic and beginning a more concerted effort to mitigate climate change.

To Biden's credit, he's focused on both issues. On Wednesday, he'll lead a virtual summit of world leaders and global health officials in which he's expected to call for the vaccination of up to 70% of the world's population within one year.

And among the climate change measures, Biden said he would request that Congress double financing to help developing countries address the challenge. It's the second doubling this year, and if lawmakers approve it would bring total funding to about $11 billion by 2024, according to Wall Street Journal data. Here at home, Biden's pledged to try to halve greenhouse-gas emissions by 2030 (from a 2005 base level). These and many other efforts will be key in the lead-up to the next big international climate summit in Glasgow this November.

At the U.N., Biden appropriately addressed nuclear negotiations with Iran and the stalemate with North Korea, as well conflicts in Ethiopia, Yemen and Israel.

"We stand, in my view, at an inflection point in history," Biden told the UNGA. "And I'm here today to share with you how the United States intends to work with partners and allies to answer these questions and the commitment of my new administration to help lead the world toward a more peaceful, prosperous future for all people."

Biden's words are welcome. Now his actions need to result in cohesion, not conflict.