Michael Carpenter - US Ambassador to the OSCE

Vladimir Putin's invasion of Ukraine represents the biggest seismic shock to European security since the collapse of the Soviet Union. The US, Nato allies and the EU are now arming the Ukrainian government. The return of hot war to Europe seems destined to lead to a new long-term cold war. Stephen Sackur speaks to Michael Carpenter, US ambassador to the Organisation for Security and Cooperation in Europe. Are we in a new age of conflict?