Over the course of history most bloody wars were caused by big Kingdoms and Empires, or so it seems? I know a lot of history, especially European and it appears to me that most bloody and horrible wars were fought between (and caused by) big nations such as England, France, Prussia, Sweden, Spain, etc. while it appears that small nation often rather stayed peaceful / on the defensive, such as Switzerland, Bavaria, Austria, Bohemia, Croatia, etc.
I can see some logic to this because, the bigger your state, the more likely you are to want even more. Also, the more people your state has the less you are attached to them and the more likely you treat your soldiers just like toys, rather than actual human beings?
The question is, are these assumptions true? Is there a correlation between the size of the state and the devastation they caused? Or do we simply just hear more about big wars such as the Punic, English-French and Roman-Anybody wars?
Bonus: I am playing games like EUIV or CKII. When I first start out as small state, I'm scared to attack my neighbors, try to care about my soldiers and be a crafty diplomat. Later on when I'm a strong country I just stomp everybody and expand as fast as I can. 10K soldiers perished in that battle? Oh well, I still have another 40K laying around somewhere. This makes me believe that it wouldn't have been much different for a ruler back in the day.
Edit: After people asked for clarification, the question is if there is historical evidence for the hypothesis that rulers are going more "mad with power", the bigger of a country (by population) they rule. By that I mean, are they more likely to engage in more wars and are more likely to make them bloodier than they need to be?
Edit2: I am aware that there are a few examples which show that a small state attacks a big one and wins, but what I want to know is the average.
Edit3: Definition of "big nation" in this context: Nation which is bigger by population than most of their neighbors.