Ethics is central to the vision and pursuit of the good international life in a globalized and highly interdependent system. Underlying the struggle for power are ethical contestations over norms and values that define who nation states are.
The balance of power on its own cannot provide a stable global order; it has to be backed by a common set of values, and international practices appropriate to the values. The shared vision of a good international society, and the ethical principles underpinning them, find their most authoritative and eloquent articulation as the purposes and principles enunciated in the U.N. Charter.
Power and principles intersect at the United Nations and also on nuclear politics. Most countries have chosen nuclear abstinence because people overwhelmingly abhor the bomb. Their very destructiveness robs them of political and military utility and renders them immoral.