Law360, New York ( October 27, 2016, 4:45 PM EDT) -- Since the Treaty of Westphalia of 1648 established modern notions of the powers of sovereign states, it has been accepted that state power extends to as far as a sovereign state can enforce its authority. Nevertheless, each sovereign is entitled to noninterference in its internal affairs. States often do respect these realities in the exercise of power. International conflict is expensive and bloody, and self-interest intervenes. International law can be understood as no more than the common sense of self-interest among sovereign states — for what is permissible for one may be permissible for others, with unhappy consequences. Likewise, self-restraint can set examples of limitations, for what one sovereign restrains itself from doing, so may other sovereign states in their joint or common relationships....