Appeasement is merely slow surrender. Remember Clement Atlee? (not sure of the spelling)
Looking the other way sacrifices the person who is the focus of attention. Remember the Holocaust?
Oh man, this is a tough one - Having spent a great deal of time reading about the 1st & 2nd World Wars, there is no easy answer to this - I guess you had to be there at the time.
WW1 - Having gone through the horrors of trench warfare (60,000 killed in 2 hours at the Somme!) those that survived went home to: The Great Depression (some reward!)
To me, it is not surprising that
A) you would do anything to avoid another war
B) be surprised if anybody turned up for it
And now an ANZAC (Australia & New Zealand Army Corp) perspective:
Our 1st contibution to world conflicts was Winston Churchill's disasterous plan to invade Turkey, with insufficient planning & medical back up - not surprisingly, we got slaughtered, but managed one of the great evacuations (no one killed) in military history. Most bizarre, is that disaster is now the most important rememberence day in Aus/NZ. Not learning from our mistakes, we turned up for WW2 and Churchill repeated his blunderings withe Greece/ Crete campiagns
To me, the most compeling cause of WW2 was the hyperinflation in Germany in the 1920's - We have a financial problem, so let's print money (sound familiar US/UK???????) - A British reporter observed an old lady carrying a whicker basket of several million marks (the cost of a loaf of bread) who was mugged- they tipped out the money and stole the basket!!!!!
With Perry storming into Japan and dictating terms as to how they should behave in US terms (and the universal European disregard of Asians) should anybody be surprised at Pearl Harbour???
Japan's big mistake in WW2 was not to embrace the countries they 'liberated' from the round eyes, but to massacre them as well -Asia could have been ruling the world 40 years ago!!!
Currently, if it was my decision, Bin Laden was with no dispute, in Afghanistan when he launched Sept 11 - day 2, Afghanistan should have been nuked - other than drugs, what has it contributed to the world??
Middle East, same scenario - other than terrorism, what have they contributed??? If they disappeared from the map, who would miss them???