In this day and age, life threatening pregnancies are so rare that they are hardly an issue. However, it is not morally permissible for a woman to deliberately take the life of her unborn child even if pregnancy or childbirth poses a threat to her life or health. However, it is permissible to treat the underlying condition or illness even if such treatment poses a risk to the life of the fetus. But as you yourself have admitted, these cases are pretty rare and even if one admits that abortion is permissible in those cases—which I do not—this kind of situation certainly does not justify the 96% of abortions that are performed for reasons of convenience, birth control, etc.
There are similarities between war and abortion in that both involve the destruction of innocent human life but in abortion only innocent lives are lost.
Here are the criteria which the Catechism of the Catholic Church sets out for a just war:
“—the damage inflicted by the aggressor on the nation or the community of nations must be lasting, grave, and certain;
—all other means of putting an end to it must have been shown to be impractical or ineffective;
—there must be serious prospect of success;
—the use of arms must not produce evils and disorders graver than the evil to be eliminated. The power of modern means of destruction weighs very heavily in evaluating this condition.
These are the traditional elements enumerated in what is called the ‘just war’ doctrine.
The evaluation of these conditions for moral legitimacy belongs to the prudential judgment of those who have responsibility for the common good.”
(n. 2309)
What damage inflicted by Iraq on this nation was lasting, grave, and certain?
Were all other means of "putting an end to it" (?) impractical or ineffective?
Considering the totality of what was involved and the political divisions here and in Iraq, how could there have been "a serious prospect for success"? It was a coin toss.
... situation certainly does not justify the 96% of abortions that are performed for reasons of convenience, birth control, etc.
I would not try to justify the 96% (or whatever) of abortions that are not absolutely necessary. I do believe that the decision as to what is absolutely necessary ultimately belongs to the woman who is pregnant.