The term 'breach' is quite generic in nature and involves any kind of non-performance, violation, non-fulfillment of an obligation, or any unlawful or disorderly act by a person, company (incorporated), or even the government in general.
The word 'peace' has several different interpretations. Some people might claim peace to be a state of non-violence or a no-war stage. Some people might also define peace to be a public policy of harmony. In some cases, peace has also been defined as a state of being secure in a society or community.
Breach of the peace has various meaning, and any breach is an action or activity that defies public policy. Violation of doctrine of behavior in the society at large is defined as a breach. Depending upon the extent and gravity of breach, legal systems can penalize people under any constitutional law, as in certain cases, it is treated as a legal offense.
The law that defines breach to be an offense with penalization, also defines the extent to which the breach should be tolerated without penalizing the offender. The parameters of such laws often change from jurisdiction to jurisdiction and from case to case.
What is Breach of the Peace?
Establishing an exact definition is quite difficult as there are several arguments and possibilities that can come into picture. A simple meaning that can be universally applied to almost all democracies and republics is "intrusion of fundamental rights and violation of public policy that is injurious to society and human beings".
Breach in General Society
Disturbance of peace in common society is not penalized till a certain extent. Loud discussions, considerably loud music, or pranks that are not harmful for the public generally don't amount to breach of the peace. Law enforcement offices do not take legal action against such pranks.
However, where an element or presence of unlawfulness is observed, there is a probability of being penalized. Similarly, any nonsensical or unlawful act that is against public policy and doctrine of behavior is treated with legal seriousness.
For example, a brawl of a drunkard is not exactly harmful, but is against the doctrine of behavior and law enforcers are authorized to intervene in such a situation. In the United Kingdom, such a phenomenon is known as breach of the Queen's peace.
Breach in International Conflicts
A treaty is an understanding between two warring nations that is initiated in order to curb a war or conflict. Where one nation violates the conditions of the treaty and resorts to military or non-military violence is treated as a breach. In such cases, international coalitions and bodies, as the United Nations or NATO, seek to intervene and establish peace.
How you interpret the concept of breach is totally up to you. From the legal point of view, it is the gravity of the offense. From the international coalition's point of view, it is the amount of human lives that are lost, but from an individual's point of view, a breach or honor of peace, is the difference between doing things in a right or wrong manner.