I know it's unusual for an answer this far down in the list to get sufficient notice to have an impact, but I think my thoughts on this are distinct from those given above, and therefore worth sharing -
Think of a child's world like a microcosm. At birth, their world is really only themselves. Over time it expands to include mommy and daddy and the house they live in, and around the time the child starts to understand language, their microcosm becomes explosively bigger as more and more concepts are grasped. By adulthood, a person's microcosm has ideally expanded to include a substantial cross-section of the world - but I doubt any of us would claim to grok the world in its entirety at any point in life. At least, though, as adults we should have the idea that the whole planet (maybe the whole universe) is our world, and therefore things happening elsewhere in it are worth knowing about and understanding: basically, the scope of our world more or less dictates what we determine to be worth knowing and retaining, so it is useless to try to teach a child something for which they have no frame of reference, or of which they cannot see the relevance.
From a conceptual standpoint, I know it would be useless to try to discuss war with my 3-year-old (beyond maybe saying that a war is a fight between a lot of people at once that usually lasts for a long time, and a lot of people get hurt). If I were to go beyond the concept of war to try to discuss specific wars with him, it would be even more useless - "Russia and the US are sort of fighting a proxy-war in Syria, using the Syrian civil war as cover, and the war against terrorism in the form of ISIL as a front and partial validation for their actions," would go over the heads of most adults, let alone children. And as complex as the situation in Syria is, that level of complexity is not out of the ordinary for modern warfare.
Geographically speaking, my son understands the concept of "city," in the sense that it is the big place in which our house is located, and he understands "state" in the sense that it is the big place where our city is located, and he even understands that there are other states (I think only because he's lived in a few different ones already). For a while, dad was in a country on the other side of the world, and we used a globe and flashlight to show him why it was morning for dada when it was night for us, and from that talk he started to get the idea of different countries, and even of "planet earth," - but again from a strictly geographical standpoint.
I am certain your 8-year-old has quite a few more concepts under his belt than any 3-yr-old could ever hope to have, but the question of "are wars real" doesn't presuppose that your son grasps the concept of a country as a political entity, which I believe is a necessary foundational concept to discussing specific current wars. It doesn't even presuppose a well founded concept of war.
I would say that rather than relying on some form of media to be a good synopsis of current events, and to have a kid-friendly filter, YOU are the best filter for your kids. Start working with them on the concepts of the world as a whole, and of other countries in it (I saw a suggestion of using a world map or globe in an earlier answer, which is a great idea, but videos can be great for this too - like the "planet earth" videos that the discovery channel made, or "baraka," or looking online at videos/pictures of the food/clothing/environment/houses/religious sites of other countries), and getting them familiar with the idea that we all live differently, but we do not live in isolation from each other, and sometimes that leads to disagreements. In extreme cases, the governing bodies of countries will choose to use violence against each other, and we call that war. These disagreements can be ideological, or they can be about controlling scarce resources, or both.
Anyway, I could go on and on in terms of specifics - because war is an extremely complex issue, incorporating religion and politics and economics and a horde of other things (including civil wars and wars with non-state actors) - but the idea in a nutshell is this: if your son is asking about whether wars happen, that is a strong indicator that he is ready for the concepts behind war, as implicit in this question is a lack of understanding as to why wars would ever happen. There is more of a request for understanding than for facts about current events. However, using real wars to illustrate concepts is a good idea - I'd suggest the conflict between Israel and Palestine, because on the surface it's an ideological war, but it is also about controlling scarce fresh-water resources in the region (such as the aquifers, and the lake in southern Jordan).
This was an area of knowledge that both my parents and my school largely ignored when I was growing up, though both told me to read the newspaper, and my mom played NPR around the house and in the car all the time. No one attempted to create any kind of global context for understanding what was going on, however, so I never cared or bothered to retain anything about it for longer than strictly necessary to satisfy teachers etc. I was so blind to the importance of events outside "my world" that even though I was in middle school when 9/11 happened, my response was, "and this matters because...?"
I do not recommend this approach. My parents more or less trusted my school to teach me what I needed to know, and schools in general are more motivated to teach children about the country they live in than about the dynamics of the world as a whole - at least within any kind of holistic framework. We did have assignments like "find an article about something happening in another country and present it to the class," but these were always curiosity pieces, not seen as relevant to our lives per se, and quickly forgotten.
It's all about expanding your son's microcosm through the teaching of concepts. Once he feels like the things happening elsewhere in the world matter to him, I would bet his learning becomes somewhat self-directed, and as long as he is reading rather than watching the news, I doubt he will see anything he can't handle - it would likely be appropriate for you to help him choose reading material, though :)