Many times in history this is true. This is also the case in the Spanish conquest of Mesoamerica. In the case of Mesoamerica, the “end” is the downfall of 3 very advanced civilization, the Aztecs, Incas, and Mayans. The means that justified this are numerous. When Cortez landed on the soil of the Aztecs, the Aztecs were expecting a god to arrive. They assumed Cortez was the god they were anticipating.
Thus, Cortez took advantage of this opportunity. He had all the proper tools to scare the civilization. He had guns, horses, and disease. Keeping on the idea of disease, the population of the Aztecs dropped 90% in one generation. This was due to the disease that Cortez had built immunity to, but remained a carrier. The population dropped steadily and Pizarro took down the Incas.
This lead to the downfall of Mesoamerica and is the reason why they no longer exist today. The means, which justified the end, is clearly seen. The means is that Cortez brought disease to the once clean civilization of the Aztecs and the end is the downfall of their society. The means clearly justifies the end in this particular case.