I think what people think in regard to war is down to the individual but I found this quote from Harry Patch who had been the last surviving Briitsh army veteran prior to his death in 2011. Obviously not all of the soldiers would have thought the war was necessary etc.

"When the war ended, I don't know if I was more relieved that we'd won or that I didn't have to go back. Passchendaele was a disastrous battle – thousands and thousands of young lives were lost. It makes me angry. Earlier this year, I went back to Ypres to shake the hand of Herr Kuentz, Germany's only surviving veteran from the war. It was emotional. He is 107. We've had 87 years to think what war is. To me, it's a licence to go out and murder. Why should the British government call me up and take me out to a battlefield to shoot a man I never knew, whose language I couldn't speak? All those lives lost for a war finished over a table. Now what is the sense in that?"