When I joined the UN in the early 1990s one of my many surprise encounters was with a large portrait of former UN Secretary-General Kurt Waldheim. It was prominently positioned above the desk of my boss, a middle-aged Austrian autocrat, whose physical and sartorial resemblance to Waldheim I found fascinating and deeply unsettling. Both men loomed unnervingly over me each time I was imperiously summoned for some menial task or mild rebuke – maybe this is why I never mustered the courage to ask him why he felt comfortable paying public homage to a Nazi stormtrooper.

My tenure at the UN straddled two Secretary-Generals: Boutros Boutros Ghali, a former Egyptian Foreign Minister, and Kofi Annan, lionised by ambitious UN officials such as myself because of his unprecedented climb through the common ranks of the international civil service right up to the top job.

But my favorite UN Secretary-General has always been the euphoniously monikered Dag Hammarskjöld. By the time of his appointment in 1953 the euphoria of the UN’s first days had waned under the growing heat and glare of the Cold War. The big powers on both sides were looking for nothing more than a safe pair of hands, a technocrat who could be counted on to know his place and to understand who was really calling the shots. They thought they had found their man in Hammarskjöld. The youngest son of a former Swedish Prime Minister, he was the quintessential diplomat, steeped in the tradition of modest and dignified public service.

In a fascinating twist of history, Hammarskjöld proved to be a massive disappointment to his political masters. More ‘General’ than ‘Secretary’ he quickly and efficiently set about using his considerable reserve powers to get the UN involved in conflict mediation and to hasten decolonisation. He conceived the idea of peacekeeping: of international forces being used as a buffer in conflict. He talked passionately, bravely and persuasively about freedom from fear being the greatest of all human rights: a perception that is as important and resonant today as it was seventy years ago. Hammarskjöld is the only UN Secretary-General to have died in office. He perished in 1961 when his plane crashed during a peace mission to the Belgian Congo – as ruined and desperate a place back then as it is now. Rumours of Hammarskjöld’s plane being sabotaged were never conclusively proved or disproved but the list of possible suspects is a long one. I’ll never forget reading, for the first time, the words he wrote as a young man:

Tomorrow we shall meet,
Death and I.
And he shall thrust his sword
Into one who is wide awake

It is fashionable, especially in less thoughtful conservative circles, to question the value of the UN. The target is an obligingly easy one. UN bureaucracy is indeed bloated and dysfunctional. The organization at times appears impotent against the greatest threats facing us today: from environmental degradation to terrorism, from irregular migration to transnational crime. Certainly the UN has failed, spectacularly, to deliver on its early, grand promises of global peace and prosperity for all.

But for anyone who appreciates the basic machinations of global politics, the idea of a world without the UN – or something very much like the UN – is unimaginable. Whatever its failings we need a forum within which international standards on everything from trade to health, from air traffic control to intellectual property can be set and adjusted as required. We need a way to channel disaster relief, to blunt the worst effects of human exploitation for private profit, to push for collective recognition of the value of immunising babies and educating girls. We need a moderating counterweight to countries that, because of their size or their military might, or the fortune of their geography, feel that they can trample on others with impunity.

The world will march on to its collective future – paying no heed to those who continue to look inward and pretend that what happens outside their national borders is irrelevant. Global governance, whether we like it or not, is the only vehicle through which the threats that are likely to kill us, destroy our freedoms or compromise the future of our planet can be addressed and dealt with.

This means that we need a decent, competent Secretary-General at the helm of the one body that exists to advance our shared interests. Another Hammarskjöld is inconceivable but another Waldheim, indeed another Ban Ki Moon (nice, but ineffectual and a poor communicator) should be equally impossible to imagine. Personally, I would be deeply disappointed if Kevin Rudd’s nomination were to succeed. Not just because his character seems inimical to the task but also because I suspect that, deep down, he is indeed the person the Security Council wrongly imagined Hammarskjöld to be: a company man who will work faithfully in the service of the powerful. Helen Clark, New Zealand’s former PM, might be better. She has a personality, and a depth and breadth of political expertise that easily eclipses Rudd’s. She has survived and thrived in her position at the top of the UN’s massive and generally well-performing development agency: an experience that will be invaluable in navigating the byzantine, cut-throat world the Secretary-General inhabits. That Clark and other leading candidates are women should be completely immaterial. It would indeed be splendid to see more women working in the upper echelons of international diplomacy. This will happen over time as women continue to shake off the shackles that have kept them back for so long. But quotas and so-called positive discrimination belong, if anywhere, at the starting gate, not the finishing line which is where the post of the Secretary-General of the UN is most certainly located.

The UN’s Charter – its Constitution – begins with the proud and bold words: ‘We the peoples of the United Nations’. This is our organization. It belongs to us and is the sum of us. We should all care about who is in charge.