THE resignation of NATO secretary-general Willy Claes is a blow to the North Atlantic Alliance. His predecessor, Manfred Woerner, who died of cancer a year ago, left him an organisation looking for a post-Cold War role. Mr Claes has won praise for his leadership as NATO re-established its reputation. For this, he will be missed. NATO will survive the upset. The two leading candidates for the succession - Denmark's Uffe Ellemann-Jensen and former Dutch Prime Minister Ruud Lubbers - have many years of experience building international consensus in fractious European meetings. Either is well qualified to take on the same role in NATO. The alliance would have come out less well if Mr Claes had fought to save his job after Thursday's vote in the Belgian parliament to lift his immunity and allow him to face corruption charges. Mr Claes is not blamed for taking bribes in person. But he does stand accused of having knowingly overlooked bribes paid by French and Italian defence contractors to his party while he was Belgian Economics Minister. It would have damaged NATO's credibility if its secretary-general was fighting to clear his name of charges relating to Europe's defence establishment. Corruption scandals at high levels of government are so commonplace in Europe that Western criticisms of official graft in Asia begin to sound hollow. Yet Europeans believe most of their leaders have reasonably clean hands. To preserve that belief in itself, and to prove to others that corruption is not inevitable, the West must not only bring allegedly corrupt leaders to trial, but also ensure those stained with corruption are not allowed to remain in positions of influence in government or international organisations. Politics must not only be clean: it must be seen to be clean. Mr Claes has done the right thing by resigning. And Belgium should be congratulated on forcing him to do it.