All those killings by the West were not due to religious reasons. For example Japan, a Buddhist nation, joined WW II due to industrial reasons. But today they changed.
Now the westerners admit that colonialism was bad. In fact Hitler indirectly responsible for the collapse of colonialim. Today Germans don't justify Nazi Hitler, Italians don't justiry fascist Mussolini.
But Islamic Jihad is rooted in religion, so you are unable to denounce it.