In the mid-1930s, when Adolf Hitler began his big push to re-arm Germany, nobody in the world really knew or understand what the mad dictator had in mind. The once-and-future enemies of Germany--England, France, and Russia, were somewhat alarmed at the initial stages of Hitler's expanding wehrmacht.
He got their attention when he sent German soldiers to re-occupy the Rhineland in 1936. Third Reich belligerence became even more apparent when Hitler ordered the anschluss of Austria in 1938 and then the military occupation of the Sudenland in Czechoslavokia in March 1939. But when, on September 1 of 1939, Adolf Hitler cranked up his war machine to invade Poland, the Allies knew that they would surely have to put a stop to German aggression, and so they declared war.
And those Allied nations, especially Britain, were really scrambling to equip their fighting men with military equipment and weapons. They were playing catch-up ball. Nazi aggression was taking them by surprise. But not really, because a few vigilant leaders, most notably Winston Churchill, had recognized the signs of war to come before everyone else did, and had advised their governments accordingly.
So its not like the British didn't see it coming; its more like they didn't want to see it coming, and so they had failed to make adequate preparations. When the necessity for defense of Europe and of Britain itself became woefully obvious, politicians began to accuse each other of dropping the ball on military readiness.
We can never really do enough in this life to prepare ouselves, individually or collectively, for the storms and roadblocks to come. Most times, governments and folk are caught unawares, blindsided, by the catastrophes on planet earth. You know the ones I'm talking about--floods, earthquakes, nuclear accidents, wars, climate change, depressions, etc. And even if people are not totally clueless about the imminent dangers, their institutions are generally underfunded and overextended when the card houses begin to crumble.
Mr. Stanley Baldwin, Prime Minister 1935-37, was a primary target of those who, in 1939 and thereafter, were looking for scapegoats. Although he had advocated for military re-armamant during his time of leadership, he had not, it seemed, done enough to get the job of military preparedness done adequately to meet the real needs when push later came to shove.
In his 1975 book The Past Masters, Mr. Harold MacMillan, who later served as Prime Minister 1957-63, wrote this about Stanley Baldwin:
"The truth is that, like many other people, he could not believe that there could be a man in the world so wicked and so lacking in any kind of moral feeling as Hitler. Baldwin's life had been cast on the whole in pleasant places. He had had to deal with a lot of people in varying degrees of good and evil in their character...(but) He had never believed that there could be a living devil. So although the full development of Hitler's career came after his (Baldwin's) resignation, he was unable to attune his mind to the thought that in this century of 'progress' the world might be hurled for a second time into the abyss of destructive war."
Nevertheless, the worst happened anyway. And I think most of us are like Mr. Stanley Baldwin.