When António Guterres steps to the podium at the United Nations General Assembly in New York this week, he will do so for the last time as Secretary-General. It is a moment that might have carried a ceremonial warmth — a valedictory of sorts — were it not for the fact that the world he is addressing looks considerably more dangerous than the one he inherited in 2017. Two major wars, each of which the UN has been largely unable to stop, frame what is almost certain to be the most sombre of his nine annual appearances before the Assembly. The conflict in Ukraine, now well into its third year following Russia's full-scale invasion in February 2022, has exposed perhaps the deepest fault line within the UN system.

Because Russia holds a permanent seat on the Security Council — and with it, a veto — the body's most powerful decision-making chamber has been effectively paralysed on the issue that most demands decisive multilateral action. A similar dynamic has played out over Gaza, where the United States has used its own veto to block resolutions that a majority of member states have supported. The result is a General Assembly that can pass non-binding declarations with broad backing, while the mechanisms designed to enforce peace remain deadlocked. Guterres himself has not been silent.

He has repeatedly called for ceasefires in both theatres and invoked international humanitarian law in terms that have irritated both Washington and Moscow at different moments. Yet condemnation without enforcement is, as many diplomats acknowledge, a language that belligerents have learned to ignore.