[1] Historically, the main obstacle to armed intervention – humanitarian or otherwise – has been the doctrine of sovereignty, which prohibits violating the territorial integrity of another state.
One of the striking developments of the past decade has been an erosion of this non-intervention norm and the rise of a nascent doctrine of “contingent sovereignty.” This school of thought holds that sovereign rights and immunities are not absolute.
From the killing fields of Cambodia to the bloody hills of Rwanda, a litany of atrocities has mocked our earnest, repeated pledges of 'Never Again.'
Following the NATO intervention in Kosovo in 1999, UN Secretary General Kofi Annan described what he termed a "developing international norm ... that massive and systematic violations of human rights wherever they may take place ... should not be allowed to stand."
No longer should frontiers be considered an absolute defense behind which states can commit crimes against humanity with "sovereign impunity.