How History Is Influencing Putin's Ambitions

Vladimir Putin has said Russia annexed Crimea because of Nato's expansion into eastern Europe.

In a televised phone-in, the Russian President said: "If we do nothing, then at some point, guided by the same principles, Nato will drag Ukraine in and they will say: 'It doesn't have anything to do with you'."

But many analysts argue Putin is playing on the psychological scars of two world wars to portray this crisis as another threat to Russian territory.

In this special report, Sky's Diplomatic Editor Tim Marshall has been examining how the former KGB officer came to power, how Russia's history has influenced Mr Putin's strategy, and what he might do next.