Which doctrine evoked God and nature to rationalize western expansion?

When white settlers from Europe moved to North America, Native Americans lost their reign on their land. They were forced out of the regions where they thrived, with many dying from battles or from the diseases that the Europeans brought over. It is estimated that more Native Americans died from diseases than from the actual battles that took place to defend their lands. In the 21st century, Native Americans live on 2 percent of the land in North Americ