It is repugnant, it is indiscriminate, it may cross borders, and yes it violates several international treaties. It also opens the door to others, and reduces us to their level.
Only one person in modern times has used bi-chemical warfare so far (certain envelope stuffers not included) - Saddam Hussein. Want to go down in history with your name next to his?

This is not a game.
This is not a war against Afghanistan (though would be be bombing the shit out of China if Chinese backed terrorists had been flying those planes?) or the Afghan people.
As much as I hate to see civilians killed - balls to 'collateral damage', they're still humans - they are not being targeted. The Taliban troops, government and the Al Qaeda are our 'enemy'.