Jens Stoltenberg, Secretary General of Nato

HARDtalk’s Stephen Sackur speaks to NATO’s Secretary General Jens Stoltenberg. The North Atlantic Treaty Organisation is 70 years old this year, but despite its achievements and longevity, celebrations are muted. That’s because NATO's cohesion and long-term viability are being questioned as never before. Is the Secretary General simply papering over the organisation’s widening cracks?Image: Jens Stoltenberg (Credit: European Photopress Agency)