Double Speak
Generally speaking, it does not serve to advance your cause by bad-mouthing your adversary. Better to give him his due, then give him his warning. Clearly and simply with no specifics, with only an end in mind.
In the case of Obama and Putin that means lining up world leaders, both East and West, to go on record as reminding Putin that while we must deal with him because of the way he is over-using the threat of death, or its reality, in his neighborhood we will limit the nature and extent of our dealings with him and his closest supporters.