Security, Armed Banditry, Kidnapping and Treaty

Assalamu Alaikum. Many cities and towns and villages in Nigeria are being attacked by armed bandits day and night, travellers are being kidnapped for heavy ransom. People are being killed by the bandits everyday and their economy is being weakened as a result of banditry. My questions are: In such a terrific situation, what can we do to ward off that evil from among us? What is the punishment of kidnappers in Islam? What can someone who is kidnapped recite to regain freedom? What Du'a can we do to destroy the bandits? Secondly, is it permissible to enter into a treaty with those bandits so that peace can reign? What does Islam say about entering into a treaty pack with bandits who have killed many people before?