Explanation:

To provide defence against external attacks

The most essential function of a state is to make Laws for the protection of the people and the property. This is a Compulsory Function. The compulsory functions include maintenance of law and order within the State. This is done not only by maintaining a police force but also by instituting a set of courts to administer justice.

The first and the most important duty of the State are to protect the life and property of its people. The State makes laws regarding life and property. It checks others from interfering into the affairs of the individual. If any individual violates the law of the State, he is punished. The State regulates social life of the individual through laws.