Historical comparisons are always inexact. No one conflict precisely mirrors another. Yet Donald Trump’s shameless appeasement of Vladimir Putin carries more than a noxious whiff of Neville Chamberlain’s failed attempt in Munich in 1938 to head off war with Nazi Germany. To be fair to the former UK prime minister – and history largely hasn’t been – his peacemaking efforts had the enthusiastic backing of most people in Britain and France who, like him, were desperate to avoid a repeat of the horrors of the first world war. Trump enjoys no equivalent public support for his treachery. Nor does he…