The story looks simple: The Ukrainian people, fed up with a corrupt and authoritarian government, revolts and chases the President out, reestablishing democracy. Unfortunately they have a big neighbour. Russia, governed by an authoritarian President, Vladimir Putin, who dreams of restoring the Tsarist-Soviet empire. So Ukraine is bullied, a Ukrainian Province (the Autonomous Republic of Crimea) is occupied by the Russians and now the Russians are starting to destabilize the country by all means, threatening to annex the South-Eastern part of the country. And isn't this exactly what Hitler did in 1938 when he annexed Sudetenland, part of Checoslovakia, and later on the rest of the country? As we all know, that led to the Second World War, because the rest of the World was not standing firm against Nazi-Germany at this crucial moment. The implications are straightforward.
The problem with this story telling is that it is too simplified, and the historic parallel is flawed.