The United Nations marked its 75th anniversary Monday with its chief urging leaders of an increasingly polarized, go-it-alone world to work together and preserve the organization´s most important success since its founding: avoiding a military confrontation between the major global powers.Secretary-General Antonio Guterres´ appeal for a revival of multilateralism – the foundation of the United Nations – was echoed by leaders of countries large and small, rich and poor. But despite largely positive speeches, it was clear that challenges lie ahead in collaborating to beat back the coronavirus pandemic, end numerous smaller conflicts from the Middle East to Africa, and achieve U.N. goals to eradicate extreme poverty and preserve the environment by a 2030 target. “Today, we have a surplus of multilateral challenges and a deficit of multilateral solutions,” the U.N. chief said, stressing that COVID-19 has “laid bare the world´s fragilities,” which can only be addressed together. “Climate calamity looms, biodiversity is collapsing, poverty is rising, hatred is spreading, geopolitical tensions are escalating, nuclear weapons remain on hair-trigger alert,” Guterres said. Appealing for a new multilateralism that draws on civil society, cities, businesses, local authorities and young people, Guterres said “no one wants a world government – but we must work together to improve world governance.” The United Nations marked its actual 75th anniversary – the charter’s signing in San Francisco on June 26, 1945 – at a scaled-down event. Monday´s mainly virtual official commemoration was a sobering assessment of the state of the world, the impact of the 193-member world body over seven decades and the struggles ahead. Some leaders appeared in native dress and in unusual settings, adding some color to prerecorded speeches. The commemoration was suspended with 58 countries waiting to speak, primarily because many leaders spoke far longer than the three minutes they were allotted. No date was set to hear the remaining speakers. As a sign of the commemoration´s importance, heads of government like Chinese President Xi Jinping and French President Emmanuel Macron spoke. US President Donald Trump was first on the list of 182 speakers, but he didn’t offer remarks. In a snub to the United Nations, the United States instead was represented by its acting deputy U.N. ambassador, Cherith Norman Chalet. The White House had no immediate comment. “In many ways, the United Nations has proven to be a successful experiment,” Chalet said. But for too long, she added, it has resisted “meaningful reform,” lacked transparency and been “too vulnerable to the agenda of autocratic regimes and dictatorships.” China´s Xi urged U.N. members to recommit to multilateralism and “work to promote a community with a shared future for mankind.” “Unilateralism is a dead end,” he said. “No country has the right to dominate global affairs, control the destiny of others or keep advantages in development all to itself. Even less should one be allowed to do whatever it likes and be the hegemon, bully or boss of the world.” Macron said the United Nations has remained true to its promises made three-quarters of a century ago: “To save future generations from the scourge of war, to assert human rights and the equality of nations, and to promote social progress in greater freedom.Macron said, “it is here and now that we have to act, with those who want to and with those who can, by exploiting all possible spaces for cooperation.” Guterres and many others said the founding of the United Nations in 1945 and the commitment to cooperation after two world wars and the Holocaust produced results. “Never in modern history have we gone so many years without a military confrontation between the major powers,” the secretary-general said. “This is a major achievement of which member states can be proud – and which we must all strive to preserve.”Guterres cited other major U.N. victories over 75 years: peace treaties, decolonization, setting human rights standards, the end of apartheid in South Africa, eradication of diseases, a reduction in hunger, development of international law and landmark pacts to protect the environment. But 25 years after world leaders adopted a platform to achieve equality for women, he said “gender inequality remains the greatest single challenge to human rights around the world.”German Chancellor Angela Merkel stressed that “the United Nations can be only as effective as its members are united” and urged new efforts “to do everything in our power” to find common responses and end “the most intractable security issues,” including conflicts in Libya and Syria.Guyana´s President Irfaan Mohamed Ali, the head of what´s called the Group of 77 and China – the main U.N. bloc of developing countries that now has 134 member states – said the commemoration “must send a strong and positive signal to the peoples of the world of our commitment to multilateralism and our resolve to strive for peace, justice and development.”Echoing broader global concerns, the president of Equatorial Guinea, Teodoro Obiang, said, “There is no justification for the huge economic gap between rich and poor countries today.” Similarly, Seychelles President Danny Faure warned that issues like climate change know no borders. “I assure you that the smallest, poorest and weakest of nations can contribute ideas as innovative … as the biggest, wealthiest and most powerful countries,” Faure said.Diplomats from the U.N. member nations managed to agree after sometimes difficult negotiations on a declaration to mark the U.N.´s anniversary, which was adopted Monday. It recalls the body’s successes and failures and vows to build a post-pandemic world that is more equal, works together and protects the planet. Richard Gowan, U.N. director for the Crisis Group, a Brussels-based think tank, said the declaration was weakened by the US opposing strong language on climate change and Britain and others objecting to China trying to insert language including its hallmark phrase, “win-win.” President Xi used it Monday in speaking about “Cold War mentality,” declaring “what we need to do is to replace conflict with dialogue, coercion with consultation and zero-sum with win-win.” Gowan said the dispute over the declaration was minor but “captures the real question that has emerged over the U.N. in 2020, exacerbated by COVID, which is: How is this organization going to navigate an era of US-China tension?” Amid those questions, the U.N. released results of “a global conversation” it launched in January, using surveys, polls and gatherings to determine what all kinds of people thought about the future. Guterres said the U.N.’s 75th anniversary is an ideal time to realize goals that were expressed, including speeding up the transition to zero carbon emissions, ensuring universal health coverage and ending racial injustice.