How to properly interpret the words and teaching in the Bible seems to very difficult, subtle, and ambiguous.

For one thing, in the New Testament, Jesus told people to love their enemies, and 'turn the other cheek' to their assailants (St Luke, Chapter 6). Obviously, the U.S. government didn't follow that specific piece of teaching in its handling of the 911 attack. What would it do if the U.S. were ruled by a Christian government instead of by a secular one, against the backdrop that the U.S. has always been a deeply Christian nation?