Does 'Ought' Still Imply 'Can'?

According to ‘ought’ implies ‘can’ (OIC), your obligation can never be to do what you cannot do. In a recent attack on OIC, Graham has argued that intuitions about justified intervention can help us determine whether the agent whose actions we use force to prevent would have acted permissibly or not. These intuitions, he suggests, cause trouble for the idea that you can be obligated to refrain from doing what you can refrain from doing. I offer a defense of OIC and explain how non-consequentialists can accommodate his intuitions about his cases