also if you're arguing that something like the roman conquests of brittania or gaul are not viewed as negatively or even defended as being beneficial, that's merely because of the passage of time, any injured parties are long dead and those peoples are no longer at war and have had more time spent peacefully. if israel had done 100 years ago to the arabs what rome had done to the gauls and assimilated them all into the israeli regime, and there was a long period of peace, it would be the same way where through the passage of time people would not view it as negatively as some war fresh in their minds.
Canada