Work cat: The responsibility to protect and international law, 2011: p. 4 of cover (The Responsibility to Protect (R2P) is a major new international principle adopted unanimously in 2005 by Heads of State and Government)

Max Planck encyclopedia of public international law WWW site, last updated July 2006; searched Aug. 23, 2011 (article entitled: Responsibility to protect; entered the vocabulary of int'l law in 2001)

UNBIS thesaurus WWW site, searched Aug. 23, 2011 (thesaurus term: Responsibility to protect; used for: R2P; "Humanitarian intervention" is listed as one of the related terms)

International Coalition for the Responsibility to Protect WWW site, viewed Aug. 22, 2011 (The responsibility to protect is a new international security and human rights norm to address the international community's failure to prevent and stop genocides, war crimes, ethnic cleansing, and crimes against humanity)

Wikipedia, searched Aug. 22, 2011 (article on: Responsibility to protect; The responsibility to protect (RtoP or R2P) is a norm or set of principles based on the idea that sovereignty is not a privilege, but a responsibility. RtoP is a norm, not a law)

Black's law dict.