Many are comparing the events unfolding in Ukraine with those at Munich 84 years ago. Indeed, if history isn’t quite repeating, it’s certainly rhyming. Russian President Vladimir Putin is doing his best impression of German dictator Adolf Hitler, disregarding international laws and invading his neighbours. Like the events in the 1930s, fingers are being pointed and questions raised as to why this aggression wasn’t stopped earlier.

Having lost the First World War, Germany signed the Treaty of Versailles in 1919 and agreed to sweeping limitations on its armaments and the demilitarisation of the crucial Rhineland region bordering France. Upon entering office in 1933, Hitler promptly started rearming, and in 1936 his troops rolled back into the Rhineland. Many, in retrospect, think enforcing the terms of the Versailles Treaty in the mid-1930s would have prevented the global calamity that later ensued.

Likewise, Russia signed a treaty in 1994 in Budapest with the United States and the then newly independent nation of Ukraine. After the collapse and dismemberment of the Soviet Union in 1991, Ukraine found itself the owner of a large stockpile of nuclear weapons. The gist of the agreement was that Ukraine would voluntarily give up its nuclear weapons in exchange for guarantees of its borders. Russia’s annexation in 2014 of the Ukrainian territory of Crimea was in clear breach of this agreement. But the West singularly failed to enforce the Budapest agreement, and Ukraine was left to rue giving up those nukes.

Hitler did not remain content with reclaiming the Rhineland. In 1938, he annexed Austria and then turned his eyes to the borders of Czechoslovakia and the Sudetenland, a region with a predominantly German-speaking population. To avoid war, during a peace conference at Munich in September 1938, Britain and France agreed that Germany could take over the area (and its intimidating border fortifications) and forced the Czechs to comply.

Putin also has had his eyes on predominantly Russian-speaking borderlands, the eastern Ukrainian provinces of Donetsk and Luhansk. He backed a separatist movement in these regions in 2014 that resulted in a bloody civil war, and on 21 February he formalised their effective annexation by declaring them independent republics and sending in Russian ‘peacekeepers’. The response by American President Joe Biden, which has so far been limited to some tepid (but growing) sanctions, will no doubt lead to comparisons with arch-appeaser British Prime Minister Neville Chamberlain.

Chamberlain’s caving in at Munich has been almost uniformly denounced for resulting in a strengthened and emboldened Hitler who was then willing to keep going and demand more. The outcome was the Second World War and the death of tens of millions.

Will a timid Western response to Russian aggression in Ukraine embolden Putin? Will he keep pushing his luck and make further demands on his neighbours that might result in a much larger war?

Yet the failure to stand up to Hitler was not the real lesson to be learned from the debacle at Munich. Critics of appeasing Hitler fail to grasp a crucial reality. For a liberal democracy to effectively oppose aggression, especially if that comes at the risk of a long and costly war, it requires the overwhelming support of the people.

There’s no doubt that it would have been easier to fight Hitler in 1936 after he seized the Rhineland, or in 1938 before he occupied the Sudetenland, but could the citizens of the democracies that opposed him have really been roused to do so? What exactly had he done that was so outrageous that the risk of starting another world war was warranted? Hitler had rearmed his nation with weapons all his neighbours were already armed with. He occupied the Rhineland, sovereign German territory. He annexed Austria and the Sudetenland, both German-speaking regions, to the overwhelming agreement of the people who lived in those places.

At the time of the Munich conference, the moral case against Hitler wasn’t as clear as it would later seem. And few in the West have been aroused to sacrifice blood and treasure to resist Russian aggression in largely Russian-speaking provinces like Crimea, Donetsk and Luhansk.

It was not until Hitler had ripped up the Munich agreement, invaded the rest of Czechoslovakia and then did the same to Poland (non-German-speaking countries very much opposed to German annexation) that the righteous outrage among the voters of Britain and France was sufficient to empower their leaders to finally decide on war. By that time, Germany had become a European military superpower.

We don’t know how far Putin will ultimately end up going. An all-out invasion and occupation of Ukraine now seems likely. But will the Baltic states and Eastern Europe be next? Will an emboldened Russia team up with China to impose a new world order? If we are on the path to another bloody global confrontation, future historians will no doubt claim it would have been easier to stop Putin in 2008 when he invaded Georgia, or 2014 when he seized Crimea, or 2022 when he invaded Ukraine.

But the sad paradox of Munich is that when thuggish aggressors can be easily stopped, there’s rarely the moral case necessary for democracies to take action, and when there is such a case, the cost of waiting needs to be measured in human lives.