What is "counter-proliferation"

Counterproliferation refers to diplomatic, intelligence, and military efforts to combat the proliferation of weapons, including both weapons of mass destruction (WMD), long-range missiles, and certain conventional weapons. Nonproliferation and arms control are related terms. In contrast to nonproliferation, which focuses on diplomatic, legal and administrative measures to dissuade and impede the acquisition of such weapons, counter-proliferation focuses on intelligence, law enforcement, and sometimes military action to prevent their acquisition.