What is the doctrine of ‘necessity’? In your answer distinguish it from thedoctrine of ‘effectiveness’

The doctrine of 'necessity' is a legal concept that justifies an act that would otherwise be illegal, but is necessary to prevent a greater harm or evil. It is often invoked in situations of emergency or crisis where the normal rule of law is suspended in order to restore order or protect the public interest. This doctrine is often used in international law, for example, to justify acts of self-defense or humanitarian intervention.

On the other hand, the doctrine of 'effectiveness' is a principle in international law that recognizes the factual situation on the ground. It is often used to justify the recognition of a new state or government, regardless of how it came into power. The doctrine of effectiveness is based on the idea that 'might makes right', and that the reality of power often trumps legal principles.

In distinguishing the two, the doctrine of 'necessity' is often invoked to justify acts that are normally illegal, but are necessary in a particular situation to prevent a greater harm. The doctrine of 'effectiveness', on the other hand, is used to recognize the reality of power and control, regardless of how it was achieved.