Vietnam War (I was 11 years old)
War in the Falkland Island
War in Afghanistan (I was 46 years old)
War in Somalia
What impacts me most are the war veterans I came in contact with.
I went to university in Fall 1976 when US soldiers were returning from the Vietnam War. My partner for my lab class was a Caucasian war veteran in wheelchair. I did everything for him.
I did my PhD in Perth and met a Vietnamese girl who fled to Australia. She's resourceful
I was working one day when I received a call to pick up a family of Somalian refugees who re-settled in New Zealand. I became their sister.
I once had a student who came from Afghanistan and he cried when he could not get any response from his family at home when the US went to war in Afghanistan.
Here's a video on a war veteran who was involved in the Afghan war. He has PTSD.
Many people say that war veterans returned with some form of mental disturbances. You can watch the video and similar videos on YouTube, and decide for yourself.
In my opinion, war is totally unnecessary. Humans have brains, and we must use our brains to interact - ie, discuss our differences and unhappiness, not by going to war.