I would counsel against taking this imperatival path, first on the rather weak ground that it is not necessary to do so.

Morality has a unique imperatival force.

Also of practical importance is the rejection of the imperatival path of sanction deployment as if international law could emerge as some form of ultimate deterrent.

However, even with this distinction, there is some difficulty in capturing the imperatival force of the 'should' in an ethical system in which intrinsic value is the only basic ethical concept.