Most of us think that the decision about the war is being made by the politicians, presidents and those who are in power. And we ( the population ) don't really think that we can influence this decision at all because we believe that we are small, powerless and insignificant.
But still we try to make anti-war demonstrations etc. This is rather not effective and we have seen it already couple of times in recent history but at least we try to do something.
Thus what can we do effectively to prevent war while being "small and insignificant" ?
Think about it...
Those who are in power and who make the final decision about the war don't work in the factories producing guns and other supplies for the army.
But you are doing it...
Those who are in power and who make the final decision about the war don't go to the front line and kill others.
But you are doing it...
Thus can you see it how you can prevent the war ?
All that is necessary is that you think and see where and how your actions support war and stop it. I know that you may have lots of excuses and justifications about it but well... in the end getting money for your survival and luxuries means that somebody else will suffer and die somewhere on the front line. And you are responsible for it. There is no way to escape this responsibility.