Munich is notorious in this respect. But this instance does not prove the rule.
Edit: In fact, it's pretty clear that if there are lessons from history we shouldn't assume we know them until after we see the pattern. And one event does not make a pattern. Appeasement has worked really well in lots of times and places.
There's a sample bias - People are likely to try appeasement when they are powerless, which makes appeasement unlikely to work.
This is our monthly thread for collecting these little gems and pearls of wisdom, rationality-related quotes you've seen recently, or had stored in your quotesfile for ages, and which might be handy to link to in one of our discussions.