Much of the Ukraine crisis hinges on interpretations of history including Vladimir Putin’s view of Nato’s expansion after the fall of the Berlin Wall.
He believes the Americans broke a promise not to allow Nato to advance one inch into Eastern Europe.
Nato did advance in the late 1990s to include almost all the former Soviet satellite republics apart from Ukraine.
One problem is that the promise was never formally written into a document.
The other is that countries like Poland or the Baltic republics have become sovereign nations, embedded in the EU or Nato by choice.
Professor Mary Elise Sarotte has written a book about it all called ‘Not one inch: America, Russia and the making of the post Cold War Stalemate’. We asked her what was motivating Vladimir Putin in this latest crisis.