The UN's ill-fated forerunner, the League of Nations, was set up 100 years ago.

Its job was to preserve peace after World War I.

But we know how the story ends. The League failed spectacularly.

By 1940, war had engulfed the world, for the second time in a generation.

Today, the United Nations faces criticism for its own inability to prevent conflict.

Wars rage across the globe from Ukraine to Syria to Sudan. The UN itself acknowledges that the world is experiencing the highest level of armed conflict globally since 1945.

So, comparisons with the League of Nations are hard to avoid.

"The United Nations was not created in order to bring us to heaven, but in order to save us from hell," said Amjed Farid, an advisor to the ousted Sudanese leader, quoting the UN’s second Secretary General, Dag Hammarskjöld.

"The hell we are living now," he told RTÉ News, "is the result of the betrayal of this concept."

He said the failure of the UN to fulfil its duties is leading the UN to be "even worse than the League of Nations," he told RTÉ News from Cairo, where he fled with his family after the outbreak of war in Sudan this April.

This week, as the UN prepares to host world leaders in New York for the opening of the 78th session of the General Assembly, questions are being raised about whether the agency is losing its relevance.

It has not gone unnoticed that just one of the heads of state of the five permanent members of the Security Council will attend next week’s high-level meetings. The US President, Joe Biden, will be here. But leaders of the UK, France, Russia and China are sending their deputies.

A security officer of the UN patrols the visitor area during preparation for the UNGA7822

With geopolitical tensions among the great powers running high, Secretary General, António Guterres, has often repeated warnings about the fracturing of the global system.

To prevent a "great fracture," he said the UN needs reform.

It must reflect the multipolar world of today, he said, rather than the one set up by the victors of World War II, (UK, US, France, China and Russia) who, with their exclusive veto-wielding power, still dominate the UN’s most senior decision-making body, the Security Council.

Modern powerhouses like India, Africa and Latin America don’t get permanent Council representation.

"I know reform is fundamentally about power – and there are obviously many competing interests and agendas in our increasingly multipolar world," Mr Guterres told a news conference this week.

"But at a time when our challenges are more connected than ever, the outcome of a zero-sum game is that everyone gets zero," he said.

Deepening division – particularly between Russia and the US and its allies over Russia’s invasion of Ukraine – hampers the UN’s ability to respond, he said.

It was a fracturing of the global system that broke the League of Nations in the end.

But it wasn’t viable from the beginning, according to Andrew Preston, Professor of American history at Cambridge University.

"The League lacked two things that were essential if it was to be successful: an enforcement mechanism; and US participation," he told RTÉ News.

"Without one of these, the League had an uphill climb; without either, it was doomed from the start," he said.

The League suffered a lack of legitimacy too, Professor Preston added, when imperial powers like Britain and France used League mandates "simply to enlarge their empires."

"So independence movements in Asia looked to more radical alternatives than liberal democracy," he told RTÉ News.

But is the UN also suffering from a crisis of legitimacy?

A deadlocked Security Council doesn’t help.

But fault lines between rich and poor members states have also been exposed in negotiations this year, over how to divvy up the riches of the High Seas, for example, or to push forward on the sustainable development goals.

Foot-dragging by the richest nations over reform of multilateral financial system, which often lands the developing world in crippling debt, left poorer member states disgruntled.

But the comparison with the League of Nations falls short, according to Richard Gowan, a UN expert at the Crisis Group, a New York-based thinktank.

Germany, Italy and Japan all left the League in the 1930s because they wanted to change the international system, he told RTÉ News.

"So far China and Russia have stayed inside the UN," he said.

"I think that is partly because they know they can do more to stymie Western initiatives from the inside than from outside," he said, "but we do see that on issues like Afghanistan, Moscow and Beijing still want to work through the UN with the Western powers."

"I think the UN is in bad shape he said," he concluded.

"But it’s still not in the crippled state of the League in the late 1930s," he said.