There’s some fuzzy thinking among Catholics on the issue of abortion and war. The argument goes like this: “Vote Democrat and innocent babies get killed through abortion. Vote Republican and innocent people get killed in an unjust war. Since you’re going to end up with killing either way, let’s ignore those issues and focus on the economy.” The subtext is, “I’m going to vote Democrat even if their candidate does support partial birth abortion.”

This is a total cop out. It is actually possible to think these things through. All it takes is a little bit of time and a little bit of thought. It is actually possible, therefore, to make a sensible moral decision in these matters.
First you have the question of proportion. How many people are being killed through abortion and how many people are being killed in the war in Iraq and Afghanistan? I don’t have the precise statistics, but the deaths from the wars are in the thousands and the deaths from abortion in our country alone are in the millions. Because of the difference in the number of deaths these two issues are not morally equivalent.
Second, we must consider the ‘innocence’ of the deaths. The death of one totally innocent, vulnerable unborn child who is incapable of self defense must be more morally outrageous than the killing of an armed opponent in war. With abortion the child killed in the womb is attacked totally and has not even the idea of proper self defense or intentional involvement. An opposing combatant has chosen (at least partially) to take up arms and be involved in a possible killing himself.
Third, we must consider who perpetrates the killing and their knowing involvement and participation. A soldier who goes into combat is trained to kill, however, he is also trained to kill only as a last resort. He is first trained to avoid killing and to take the enemy prisoner if at all possible, and he is supposed to treat the prisoner humanely. In war this does not always happen, but consider the abortionist or one who procures an abortion: in every case they set out intentionally to kill and to do nothing but kill an innocent human being. Politicians who support abortion therefore enable those who wish to kill an innocent and defenseless child. Even if the particular war is unjust, the soldiers and politicians who instigated the war were doing so (even if in a debased way) not to promote killing, but to promote a final goal of justice and peace. 
Fourth we must consider the possibility of self defense. An enemy combatant can arm himself and fight back. An unborn child is attacked while totally defenseless and is unable to defend himself in any way.
Fifth, we must consider the innocent deaths of those who have died in the Iraq war. The largest numbers of those killed have been killed by fellow Iraqi terrorists, not by American soldiers. Along with this we must consider the intention of the American soldiers. They have not intended to kill innocent civilians, even if some have been killed. Furthermore, they have been trained not to promote the terrorist attacks that have killed so many, but to stop them–even at the expense of their own lives and through their military operations.
Notice that the arguments above are not concerned with the justice of this particular war or the injustice of it. I happen to think it is an unjust war and I wish we were not involved in it. This is a separate argument altogether, and one that can be properly put by those who wish to argue one way or another.
However, to say that involvement in an unjust war in which people are killed is the moral equivalent to abortion is lazy, dumb, or willfully rebellious against simple truth.