This is nonsense. It is abortion when the early, non-viable fetus is removed from the mother’s fallopian tubes. That is one of the rare times when abortion is moral, but it’s liberals nonsense to pretend that this is not abortion. I was present when an OB/GYN performed what she called her “first abortion ever” to save my sister’s life (after my brother-in-law was hit by a drunk driver and could not be there) for exactly that reason.
I think you confuse terms because you leave out intent. Intent is what divides killing from murder, unintentional homicide from murder in the first degree. If one considers the morality of self defense and just war; truly the intent is not to murder those that want to kill you but rather to defend yourself using the proportionate means necessary to assure you survive.
I can tell you that myself as a Catholic, the Catholic Church gas extensively elaborated upon and developed better than any others the moral landscape on this issue.
Abortion, simply put, is intentional murder. Reasons do not really matter when the intention is evil. In other words good ends never justify evil means.