Evil has many faces.
Once it was a bespectacled jackbooted 'specialist' working assiduously to increase the throughput of the gas chambers.
Today it is a bunch of drunken louts on a hilltop cheering as bombs and shells destroy apartment building after apartment building along with their occupants.
Or, the fanatics steeped in religion who brutally kill people because they hold different beliefs.
Evil arises in the human heart. When it fills it to the brim the heart becomes a blackened, putrid bit of flesh, instead of the repository of the feelings and emotions that make us human.
When Evil fills a heart it makes it easy to commit the greatest of all crimes − kill another human being. When Evil fills the hearts of a whole people it makes it easy for them to annihilate another people. It makes no difference if that is done to seize their land or to purify one's own; the crime remains the same.
Such manifestations of Evil pose a challenge to the rest of humanity. Either we stand up and condemn or oppose them, or we become complicit in the crime − there is no middle, neutral ground.
While few indeed can summon up the shining heroism of a Rachel Corrie, or even the courage of a young Lucas Koerner (who stood up in Jerusalem to say: Not in my name), it is important to disassociate oneself from the abomination being perpetrated by bearing witness to one's opposition, each according to their circumstances. That is how one affirms one's own humanity.
As for those who support, excuse, or even condone this crime, or use mealy-mouthed circumlocutions to avoid showing their true colours, they become a part of the Evil abroad in the land. The Evil descends into their hearts, and they begin to recede from humanity, and join its enemies.