Globally speaking it's rather clear that this was not the case. For example, the Taiping Rebellion in China, which took place between 1850-1864, was a religious conflict between the Imperial Chinese Qing Dynasty and the Taiping Heavenly Kingdom, a breakaway state following a strange millenarian sect of Evangelical Christianity, whose leader Hong Xiuquan claimed to be the younger brother of Jesus. This conflict claimed at least 20 million lives (and that's the low end of the estimates) because the two opposing forces both consistently targeted civilian populations. Depending on the estimate you go by, it's either equivalent to 1/4th of the deaths of the World Wars combined, or almost 1.5x as deadly. Basically all of the Chinese internal struggles before the fall of the Imperial Manchus were rather divorced from the two concepts you put forward. The American Civil War was purely profit-driven; depending on your view of imperialism and its motives, you could also argue that colonization efforts were based on economic reasons more than any sort of nationalism. Certainly the Scramble for Africa had nationalist elements built into it, but this was mostly around the time of WWI and the question of the German Empire as a colonial nation, so imperialism also probably cannot be described in that way.

That said, in Europe, socialism and nationalism were both reactions against the still openly aristocratic and economically abusive societal trends of the time, and later against the poverty and social instability caused by the fallout of WWI. So, in a European context, you'd be hard-pressed to find a conflict that didn't have one of these elements in it.