Yes, Native American's had a different concept of war than Europeans did. In Native American wars the purpose was not always to kill the opponent, but to show them you could kill them but spared them. Winning a war by killing all of the other side was beyond the concept of war for Native Americans.
The Spanish Conquistadors conquered the Native Americans because they wanted their gold.
Spain
smallpox
smallpox
The Europeans started to use the Native Americans as slaves.
One result of the loss of Native American lives to disease is that the Native Americans moved farther away from the Europeans. Another result of disease among the Native Americans was their lack of people to fight the Europeans for land.
Disease
Mostly smallpox
smallpox
Native Americans received disease. Although they lost much, the introduction of disease especially STD's.
Aids
syphilis