What is the importance of martial law?

Martial law seeks to maintain public order by military means in times of a crisis, when the normal civilian institutions of justice either cannot function or could be deemed too slow or to ill-equipped for the new situation. Usually martial law is very strict and there are no Constitutional safeguards in effect until after the martial law period is declared over. It reduces some of the personal rights ordinarily granted to the citizen, limits the length of the trial processes, and prescribes more severe penalties than ordinary law.

In many countries in the world, peace can be unsustainable. When that gets over the edge with massacres and genocides, the military takes over with martial law.