In Peru, the native inhabitants, the Inca empire, were ruled by Atahualpa. The initial objective of the Spanish empire, or more specifically, the conquistador Francisco Pizarro, was to eliminate Atahualpa. This was done by kidnapping him, forcing him to pay ransom for proposed release and then murdering him regardless. Subsequent to his murder, his empire, the entire local population of native inhabitants, were subjected to forced labor.
On the contrary, in Mexico, the native inhabitants were the Aztec empire, ruled by Moctezuma II. The Aztec empire were far less resistant than the Inca empire, partly because they did not believe that the Spanish empire posed a threat. The Spanish empire, or more specifically, the conquistador Hernan Cortes, capitalized upon this opportunity by annihilating the majority of the population, massacring many innocent lives of these defenceless native inhabitants.
From all three of these stories of colonization, we may deduct that relatively inhumane processes were used. In the former two, in both North America and Central America, the population of native inhabitants were managed by mobilizing them as forced labor. In South America, with the exception of in the Inca empire, the population of native inhabitants was managed by massacring them, extinguishing them completely.
The objective of colonization is to expand an empire, in order to garner power, resources and wealth. It is not to eliminate native populations. All of these native populations are innocent. They are simply protecting their local regions, just as the empires would if their local regions were colonized in similar fashion. In some cases, they were not even defiant. In Mexico, the Aztec empire were hospitable, they believed the Spanish were gods. It is peculiar that the most damage was done in the Aztec empire, were the native inhabitants were least hostile.
In my opinion, from this we may extract an important lesson about these empires. They care only for themselves. They are unable to comprehend that just as they wish to expand their empires, alternative empires, such as the Aztecs and Incas, wish to keep theirs. They care little about hospitality and diplomatic manners of colonizing any given region, rather colonizing it in a matter that is most expeditious and effective. In human nature, the most moral manner of doing things is not always the most expeditious and effective, albeit it may be the most profitable.