Shashi Tharoor, my former boss at the United Nations, was - and perhaps still is - a fiery defender of the United Nations. He was once asked by a BBC interviewer how did the UN feel about the "i" word, i for irrelevant? Mr. Tharoor, without missing a heartbeat, replied, "Oh, I think the 'i' word for us is actually 'indispensable.'"

That was about 15 years ago. Today, I wonder how does he feels about the dreaded "i" word, and yes, I mean "i" for irrelevant.  For a starter, I would mention three recent events.

Last month, the United Nations envoy for Syria, Staffan de Mistura, walked out of an international humanitarian task force meeting in Geneva within minutes after it had opened.  All major parties involved in the conflict were present, including the Russians and Americans, and their proxy fighters, the Assad regime and the "moderate" rebels fighting the government.  After spending months and weeks talking to all sides on the need for a humanitarian pause so that urgently needed food aid could reach the people of the besieged towns of Madaya, Zabadani, Foah and Kafraya, the parties were still nowhere near an agreement. It made "no sense" to continue talking just for the sake of talking, he said, and walked out of the meeting.

The same day, August 18, an Associated Press photographer captured the image of a boy rescued from the rubbles of Aleppo.  The city had suffered constant bombing from all sides, trapping nearly half a million people in death throes. The latest bombing, by all indications, was by the Russians, a permanent member of the United Nations Security Council. The boy – his name we later learned is Omran Daqneesh - was placed on an orange chair, his face and hair dusty and bloodied, his eyes dazed. He was completely silent, not even a teardrop in his eyes. Within hours, the photo went viral, making him the new poster boy of humanity's collective failure to stand by the neediest.  

As it happens, the UN has been begging the warring parties and their patrons for a 48-hour humanitarian pause, but the UN's big honchos, the five permanent members of the Security Council, on whose shoulders the world placed the heavy burden of maintaining international peace and security, just could not agree on how to proceed. On August 22, the UN Under-Secretary-General for Humanitarian Affairs, Stephen O'Brien, met face to face with the "gang of five" and looked straight into their eyes.

"I'm not going to pretend – I'm angry, very angry," he said referring to the carnage in Syria for the last five years. "This callous carnage that is Syria has long since moved from the cynical to the sinful," he said. Looking bleary and sounding hoarse, the UN Under-secretary-General begged, "So please: now is the moment, this instant, to put differences aside, come together as one, and stop this humanitarian shame upon us all, once and for all."

There was pin drop silence in the Council chamber, long faces of the world's powerful cast downward.  Meanwhile, thousands of miles away in Aleppo and other cities in Syria, bombs continued to drop.

So why is it that the UN cannot do anything about the slow strangulation of an entire nation? As a former UN staff member, I am quite familiar with the stock answer. "This is the responsibility of member states. The world should hold them accountable."

There is logic to this answer. Sure, the UN is the sum total of its member states, but how can we not recognise that their failure to carry out their solemn commitment to "peace and international security" is actually the failure of the United Nations?  When the organisation's key members fail to perform their duties year after year, the relevance of the organisation itself comes into question. There is no two-ways about it.

Time and again, the UN has found itself on the wrong side of history. Nearly 50 years ago, in 1971, Bangladesh faced a similar annihilation at the hands of an occupying army. For nine months, the Security Council failed to meet – not even once – due to disagreements among its key members. Finally, when Bangladesh – with the help of the Indian army – was on the verge of winning its freedom, the Security Council woke up from its slumber to stop Bangladesh's march to freedom. The big honchos spent several futile days and nights, negotiating a ceasefire. Neither Bangladesh nor India heeded to their maneuverings, and thirteen days later, on December 16, Bangladesh was finally free. Five days later, the Security Council managed to adopt a resolution calling for a durable ceasefire. By then, of course, all guns had fallen silent. The resulting laughter could be heard even in charred villages in Bangladesh, thousands of miles away.

Then Secretary-General U Thant memorably captured his own frustrations in getting the big league boys to act on a humanitarian crisis. In his memoirs, View from the UN, he wrote: "Throughout the struggle, the United Nations had made no move to act; my pleas and warnings to the Security Council, both privately and publicly, fell on deaf ears. The Council was immobilised, both by the refusal of the parties directly involved (India and Pakistan) and by the major powers, to face up to their obligations under the Charter to confront the issues forthrightly."

Throughout 1971, the UN's principal preoccupation was to encourage Bangladeshi refugees to return home, although there was no guarantee of their security. When in June, a correspondent asked U Thant why the UN had not come to grips with the real problem of Bangladesh, and instead had dealt only with peripheral humanitarian problems, the Secretary-General stammered to acknowledge that the entire episode was "a very terrible blot on the page of human history."

That was not the last time the UN was left watching people die. The Bangladesh genocide was followed by similar carnages in Cambodia, the Balkans and Rwanda. Unable to get its "gang of five" to agree on political action, the UN has increasingly turned its attention to humanitarian and emergency assistance. Useful work no doubt, but that only makes the UN an expanded – and more glorified – International Red Cross. Since the Red Cross does not have to deal with political prima donnas, it could be more effective, only if it could be equipped with more resources. Why, it could even replace a hobbled United Nations!

As for the question whether the UN is "irrelevant" or "indispensable", go ask young Omran and hundreds of thousands of Syrians like him. I have no doubt what the answer would be.

The writer is a journalist and author based in New York.