Jens Stoltenberg - Nato Secretary General

President Biden prepared for his Geneva summit with Vladimir Putin by reassuring his partners in NATO that America is back in the saddle; committed to the defence of European allies and determined to lead the alliance's response to evolving geographical and technological threats. But how convincing is this reassurance? Stephen Sackur speaks to NATO Secretary General Jens Stoltenberg. Is rhetoric being used to paper over NATO's cracks?