I have coincidentally been reading The Drift to War by Richard Lamb which describes in detail the period from 1929 of "The series of errors in British policy that led to World War II". Admittedly we look back with the benefit of hindsight, but even so the entrenched views and missed opportunities are staggering.
The key to it all was Austria. The key to Austria was Mussolini. He was against the Anschluss as it would bring the Wehrmacht to the Italian frontier. However, his invasion of Ethiopia caused great anger in the UK, and the sending of Italian 'volunteers' to the Spanish Civil War to fight for Franco was opposed by Britain and France. These two issues obscured the big issue of stopping Hitler bringing the various German speaking populations surrounding her into the Third Reich by military intervention if needed.
Once he had Austria then Czechoslovakia could be invaded from the south, outflanking the formidable defences in the West. Nonetheless there was a mini entente to the east whereby Soviet troops and supplies could counter such an invasion, and some 40 Soviet bombers were flown to Prague by Czech pilots. Also, a possible French invasion of Germany in the West could overwhelm the very reduced German forces there. The German General Staff were so worried that they planned to arrest Hitler and declare martial law if he invaded Czechoslovakia.
As we know all too well, such an opportunity was lost thanks to Neville and his bit of paper. Interestingly he nursed a large chip about his now deceased elder brother Austen having had all the attention from his parents. Of such trivia are great events created...
The author claims that the year gained before WWII benefitted Germany more than it did its opponents (including the UK). One in four of the tanks alone in the French Blitz Krieg came from the Skoda works!