Amid Russia’s invasion of Ukraine and China’s rise as a strategic competitor, NATO is faced with a rapidly shifting geopolitical environment. Moving forward, the alliance’s greatest challenge might come from within, as democratic backsliding continues to plague some member states. Ambassador Douglas Lute, a former U.S. permanent representative to NATO, discusses NATO’s efforts to deter further Russian aggression, how China’s differing view of world order makes it a competitor to NATO’s mission and why shared democratic values are the glue that holds the consensus-based NATO structure together.