I beg to differ. These people DO have the capacity to discern between good and evil. But they have those concepts completely mixed up, because their moral compasses are totally upside down. In a battle between good and evil, they most definitely do choose sides. They choose the side of evil. They choose to feel compassion toward the bad guys and to condemn the good guys. They have gone beyond moral relativism. They have crossed that line. They actively defend and support the bad guys, while they condemn the good guys and try to portray them as the bad guys. They never weep for the victims of terrorists, yet they express compassion for dead terrorists. Their compassion is a sham and totally misplaced, because it's always expressed for the guilty and never for the innocent.
Such people are not blind. They simply have the concepts of good and evil inverted and reversed. That's why the Bible says, "Woe to those who call evil good and good evil." It is precisely these people which the Bible refers to.
My reason for saying that they are incapable of discerning good from evil comes from the fact that basically all of Europe and a large portion of America has declared God to be dead.
The Bible says "The fear of God is the begining of wisdom". Having rejected God, these people are left to flounder and flail about, grasping at what, to the human mind, appears to be reasonable and "fair." The rejection of God does not mean that one then believes in nothing; as a matter of fact, the rejection of God leaves a vacuum into which all manner of deception and "damnable heresies" then falls. The person who has no knowledge and fear of God has no hope of being able to know the difference between good and evil. There is no absolute truth; everything is relative and open to discussion and moral equivalence.
People who have turned against absolute truth will then believe anything. The people like the one who wrote this letter have made the choice to reject the only true Source of absolute truth in the universe and therefore have chosen to leave themselves open to the opposite of truth which is, of course, deception and untruth.
This is what we are seeing during the course of this conflict. The only good thing to come out of this is the stark desolation we see from those who don't know God and as a result live in a world of confusion, with no moral compass, no concrete moral foundation, and no One to Whom to turn for comfort in the midst of terrible circumstances.