To many who know the UN well, the organisation has grown bloated with age, is underfunded and shows few signs of righting itself.
That was evident when an internal report by the UN health agency revealed that cronyism and incompetence in its leadership may have contributed to the spread of Ebola.
Since the UN was born after World War II, it has grown from 51 members to 193. As it approaches its 70th anniversary next year, it is hobbled by bureaucracy, politics and an inability among its five most powerful members to agree on many things, including how to bring peace to Syria.
The paralysis shows in the debate over what the UN itself should be. Most nations agree that the 15-member Security Council, the UN's most powerful body, must adapt to address threats to international security. Yet all reform proposals are repeatedly rejected.
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One result is that Russia, a close ally of Syria, has blocked all Western resolutions that would pressure President Bashar Assad to end the conflict there.
Certainly the UN has had some success in its primary mission to stop "the scourge of war." A record 130,000 UN peacekeepers are deployed in 16 hotspots, and it has responded to an unprecedented four simultaneous, top-level humanitarian crises: Iraq, Syria, Central African Republic and South Sudan.
UN spokesman Stephane Dujarric argues that the UN has adapted since its founding. He said Secretary-General Ban Ki-moon has worked with member states "to make the system more flexible and even more responsive" to needs in many areas, including collective security, international transport, health and human rights.