Pope Benedict on Death Penalty:
Not all moral issues have the same moral weight as abortion and euthanasia. For example, if a Catholic were at odds with the Holy Father on the application of capital punishment or on the decision to wage war, he would not for that reason be considered unworthy to present himself to receive Holy Communion. While the Church exhorts civil authorities to seek peace, not war, and to exercise discretion and mercy in imposing punishment on criminals, it may still be permissible to take up arms to repel an aggressor or to have recourse to capital punishment.
Indeed. . and it was the Catholic Church that developed the concept of Just War. . .to ensure the aim of the war was just, not evil, was defensive not offensive, that steps were taken to lessen the suffering of innocents. (Apparently islam has not the brains nor compassion to act in a Godly manner when it comes to war, intent and suffering.)