They are the two great moral problems. Theodicy means the justification or vindication of God: how does the existence of evil ("existence," what a wimpy word for something so rampant) not disprove either God's existence or goodness?
And the other problem is the balance of evil we humans place our own thumbs on, playing godlet. Does the end ever justify the means? Can we do evil -- take life, cause pain -- for a greater good? When can we? And if we don't, don't we still? And don't we pay, don't we have to pay, even when we are right?
If you use an “over the horizon” attack, you are responsible for the deaths of people — some combatants, some not. This is unsatisfactory. On the other hand, if you don’t use an “over the horizon” attack and instead, say, send troops, aren’t you then responsible for any deaths or other casualties among those troops that would otherwise not have happened? If you use “moral suasion” and diplomacy, when military action could have shortened a conflict, don’t you bear some responsibility for the suffering of people hurt by the conflict? If you do nothing, aren’t you then responsible in part for what comes to pass?
If you adopt the notion of “doing no harm”, aren’t you then responsible for harm that comes because of what was left undone, or done some other way? [...]
If you use torture, you’re certainly responsible for the harm that causes. If you refuse to use torture, no matter how many people might be harmed or killed, don’t you then necessarily have some responsibility for that harm as well?
Responsibility, he decides, is the key word. Read the whole thing.