I thought about adding more context to my reply - like yeah, to the slave OWNERS it's not so bad, while to the SLAVES it's not so great... (even though they were given sammiches sometimes, I presume you know the history of that little gem of a comment:-)
I was not privy to their deliberations but I could guess that they (1) might take into account what was known at the time, and (2) even for something as bad as slavery, if they helped prop up a democracy that would one day lead to their freedom, it still isn't nothing in that regard, even if it is insufficient on its own?
Similarly, the League of Nations did not work out directly, but even serving as a model of failure, did set the stage for the United Nations?
Hrm, maybe they assigned things to separate categories, so that like once someone already earned the absolute minimum score on something like on a scale of 1-5, he gets a score of 0 on civil liberties, but then other categories are still allowed to raise it up.
And I dunno about not entering the war. People could debate how and why, but "appeasement never works", and watching as all our allies became conquered nations and knowing that they'd later come back as enemies... even if only decades later, I am not so sure that the question as to whether or not to go to war is as simple as "war = bad, always". While it is true that there is no "winning" a war, only differing degrees of losing, the worst-case scenario of losing all your allies and then eventually yourself is fairly bad.