What is Putin’s big plan in Ukraine?

We woke up in a different world today, said Germany’s foreign minister, into a world suddenly thrust right back into the darkest days of the Cold War.

President Putin bent on rewriting decades of history and reasserting Russia’s place as a great power, unleashing all the military might of his state in pursuit of his long-held ambition, marching into vast swathes of Ukrainian territory that he claims should always have been under Moscow’s control.

Jonathan Rugman reports on what Putin is trying to achieve.