Russia has invaded Ukraine amidst an ongoing eight-year civil war between ethnic Ukrainians and Russian-speakers in the east, and following decades of tension and warnings over the prospect of NATO membership for Ukraine. Some fear we could be on the verge of a global war between nuclear superpowers. But how did we get here? Jonathan speaks with two Russia experts with decidedly different views on that question – Alexander Duleba, head of the Eastern Europe Research Program at the Slovak Foreign Policy Association, and Richard Sakwa, Professor of Russian and European politics at the University of Kent in the UK.