Moral obligations are not the same thing as national obligations. And fulfilling one's moral obligations by invading other countries can lead to unintended consequences. What's that? You don't know what "unintended consequences" are? Okay, here you go.
Unintended consequences are outcomes that are not (or not limited to) what the actor intended in a particular situation. The unintended results may be foreseen or unforeseen, but they should be the logical or likely results of the action. For example, students of history often conjecture that if the Treaty of Versailles had not imposed such harsh conditions on Germany, World War II would not have occurred. From this perspective, one might consider the war an unintended consequence of the treaty.
You see, when you campaign for ideas like "taxes are bad" or "poor people are too fat anyway," sometimes there are consequences, like people suffering or infrastructure crumbling. Or you vote for Bush and our country is at war, in debt, and--now this is the important part--considered immoral for creating so much death and destruction.
We can also see the basis for Megan's moral foundation; God tells you what's right or wrong, because nobody could actually figure out what is good and what isn't without His Glorious Morality.
I can't see how you can have any sort of meaningful faith and divorce it from
your voting decisions. Religious faith is supposed to tell you, among
other things, what is right and wrong. How are you supposed to vote
without reference to your notions of goodness?
Well, let's think. Stealing and murder and lying hurt people, so they're wrong. Wow, that was easy! And I didn't need to drag a single archaic deity into it.
[Heavily edited after posting.]