// Britain and France were infected with a Liberal pacifist desire for peace ... //
This feels overly simplistic. France, for example, ought to have some sympathy for bearing the brunt of the Western Front fighting: it was their land that was devastated, many of their young men who died or were injured. According to some sources over 4% of their population died in that war, proportionally twice as many as for Britain; and around 2.5 times that counted as military wounded (again, far more than in the UK).
German losses were proportionally similar, it is true, but if for France victory felt Pyrrhic, then for Germany defeat was bitter, and it was easier to motivate them to get revenge, etc. This, too, is a massive oversimplification in its own way, but it's still relevant to note that France had no desire for another bloody war, whereas Germany had no desire for another bloody defeat, and the two positions are completely different.
But then if France isn't up for the fight, why should Britain be? Just practically, you can't really expect to fight a war on the continent without French backing; to say nothing of the, mistaken in retrospect, decision by the UK and other allies to limit their naval power in various Treaties over the 1920s. But at the time even that wasn't entirely unreasonable, and in any case seems to have been largely driven by the US -- another reason why Britain might have been reluctant to pursue war in the 1930s.
I suppose that point passes the "blame" to the US's own pacifism, or similar, and that's not my intention, especially when I can hardly claim to be an expert on interwar history. But in general we're at the "we don't want war because we have seen how devastating a modern war can be, and besides we're in no fit condition to fight one" point, which at least provides a coherent, though only partial, justification for Chamberlain's approach. I *do* think that towards the end (1938-1939) it was mistaken, but a lot of things went wrong in the build-up to the war and it's simplistic and unfair, in my view, to blame the "infection" of a "liberal pacifist desire for peace" for it. In the long run, that could even have worked, but for a Germany that was wounded, angry, and all too eager to embrace an equally deranged 'saviour'.