The biggest exchange of prisoners between Russia and the West since the Cold War included opposition leaders, journalists and prisoners of conscience. Our correspondent accompanies America’s defence secretary on a tour of Asia designed to bolster military alliances (12:17). And why King Charles counts his swans every year (21:15). Listen to what matters most, from global politics and business to science and technology—Subscribe to Economist Podcasts+For more information about how to access Economist Podcasts+, please visit our FAQs page or watch our video explaining how to link your account.