I may be wrong in that, but not I think in putting the questions. In our modern democracy the government needs not a unanimous but a general support for war before it orders our forces to fight.
Wisely used history can give pleasure and provide us with a useful tool; but we should not become its slaves.
It depends on how it is done but what we are drifting into, which is that people grow up without any sense of a spiritual dimension to life, is just impoverishing.
We should be wary of politicians who profess to follow history while only noticing those signposts of history that point in the direction which they themselves already favour.
There are thus great swathes of the past where understanding is more important and reputable than judgement, because the principal actors performed in line with the ideas and values of that time, not of ours.
But Germany will always suffer, I fear, from the intensely dramatic character of the crimes of the Third Reich.