Hard feelings around. One hard fact though, - WW1 was a conflict of quite complicated political issues that spread around. There was not much difference of the sides AFAIK. If you wanna pull something bad on Gerry, than it is that they were the openers of the first gas cans. (Ypres)
WW2, - you have leather booted tyrany coming it's way, first by bullying, taking powe, then murders, confiscations imprisonments and deportations.
Then you have military buildups, annexings, then invations, and when the old Tommy and Pierre had enough of it, WAR. WW2 starts as a World war with Britain and France becoming allies to the Polish against Germany.
WW2 came to the USA by Germany declairing war on the USA because of the tripact.
Lots of hard desicions to be made. Axis decided to go on the dark side. Tying their populace up by application of all methods, their control of the people was incredible, and their propoganda was such as well.
However, when it comes to the business of the camps, it becomes more interesting. You see, what was going on in there was not supposed to escape to the German public. As a back up, the public was either supportive enough to co-operate, or afraid.
So, if you look deeply into items like the Holocaust, - the whole "job" was not intended to escape to people. It almost did though! Today you have debates about it. Just a little less survivers and documents, and it would be a debateable thing! It was meant to happen in such a way that there were no survivors and no documents. A corpseless murder in a dark alley.
Then you can put your eyes to a camp like Dachau. You have all sorts of folks in the guards department. They get haired out if they break or are too soft. They get to know most about what's going on, and the superiors definately do. The prisoners do. The prisoners surviving camps like Sachsenhausen or Dachau normally do not belive that the whole German population did know indeed. (well, I don't buy that one quite).
So, back to the dog guy. I'd ask him a few questions I think. He doesn't have to be a war criminal, - and either way, his story would be worthwile to hear.