Nuclear weapon
Historical analysis of nuclear weapons deterrent capabilities has led modern researchers to the concept of the stability–instability paradox. Nuclear weapons confer large-scale stability between nuclear weapon states, as in over 60 years, none has engaged in large-scale direct warfare, primarily because of nuclear weapons deterrence capabilities, but they are forced into pursuing political aims by military means in the form of comparatively smaller scale acts of instability, such as proxy wars and minor conflicts.