keep the peace

to prevent fighting or difficulties The judge made her sign an agreement promising she would try to keep the peace with her husband for one year. Troops were sent in to keep the peace in the region.

Maintain public order; prevent strife. For example, President Clinton ordered troops to Bosnia to keep the peace. This expression dates from the 1400s and was originally used more in the first sense, that is, of police keeping public order. It gained extra currency in the second half of the 1900s when military forces were sent to diverse places-Lebanon, Haiti, Bosnia-to stop warring factions.

To maintain or observe law and order: officers who were sworn to keep the peace.