During WW2, Yugoslavia had a very strong guerilla partisan movement that created a lot of problems to the nazis.
Being caught as a partisan, or helping them, meant the whole family (often even the entire village) got killed.
My friends mother was a small child during the WW2. She told me they had a German patrol in their village on one occasion. The German soldiers were nice to them and she had started talking to one (our province had many Germans and many people spoke some basic German). And told him her name is XXX, but her partisan nickname was YYY. Her family was helping the partisans. The soldier just smiled and walked on. It is to be expected he knew what they would face had he reported it and it took some personal courage to be hush about that. She doesn't tell many war time stories and none seem invented so I believed this one.
My grandfather fought with the partisans, got wounded, but survived the war. Another friend of the family had survived a nazi death camp. Both of them never hated Germans and said most of them just fought for their country. Noting a huge difference between Wermacht and the SS. I don't think an average German soldier was any worse, or better than most other soldiers.
In the recent history my country did some horrible war atrocities. Not everyone could escape the draft, even if they openly opposed the policy and the wars. Some got killed, wearing the uniform of the country who's regime they had openly opposed. You get drafted, sent to the front, and shot at - you can either shoot back and obey the orders, or get shot by one side, or the other.