Unlike the air forces operating during World War II, Bashar al-Assad isn’t trying to kill enemy noncombatants. He’s trying to kill his own people.

Several explanations are available for Assad’s use of extreme military tactics. Some believe that the Syrian president’s strategy is designed not just to defeat the rebels but also to scare off anyone else who might have ever wanted to join them or to persuade his opponents that their cause is futile. Others think he is motivated by bitterness: If he can’t control a town or neighborhood, then he prefers to see it reduced to rubble. Some see a grim silver lining in this strategy: If Assad is destroying Aleppo, that may mean he no longer expects to win it back.

Recently I’ve also heard another explanation: Aside from creating fear and destroying defiant towns and cities, Assad is deliberately provoking and defying the West in general and the United States in particular. By firing on his own people and carrying out mass slaughter, he is crossing every “red line” the international community has ever set. Each new atrocity sends a message to the Syrian opposition: Nobody in the outside world will help you. By that logic, Assad will soon be using chemical weapons, if only because we’ve told him not to. And what then?