For those who claim this is a Christian nation and claim to be Christian, read Matthew, Chapter 22, Verses 34 through 40.  After you read it, go back and read it again and again until not only do you understand what Jesus commanded of you, but until you put his commandment into practice.  If you cannot do so, or willfully refuse to, please do not call yourself a Christian because regardless of what ISIS is or stands for, Jesus did not condone what Ms. Peterson is suggesting.  As for me, I am Christian and faithfully try to follow all of Jesus' teachings; this doesn't make me better than anyone else as I fail somewhere along the way each day but try with Grace to go forward and amend myself daily.
May God have Mercy on all regardless of whatever beliefs they may or may not have.