Because of the existence of so many states, countries, nations, and other jurisdictions that have their own codified laws, it becomes difficult for such jurisdictions to maintain and exercise their laws amidst the laws of other jurisdictions. However, a legal tradition developed that allowed jurisdictions to respect the laws of other jurisdictions. Such a tradition is referred to as comity.
So many levels of governance exist—local, regional, national, and international. In order to ensure that order is maintained and each law is respected by every individual, it is important for other jurisdictions to recognize and acknowledge the legitimacy of another jurisdiction’s laws. International law refers to this type of respect among jurisdictions as comity of nations.
The purpose of comity is to ensure that order is maintained in every aspect of governance. This may mean that a law invoked by a person in one country must be respected in another country, as long as it does not create any other illegal or illegitimate ramifications. Thus, there becomes a need for countries, nations, or jurisdictions to mutually accept certain laws, rulings, and policies in order to prevent legal problems from arising.
For example, a couple files and successfully completes divorce proceedings within the jurisdiction of the US. This divorce must also be recognized in other countries, leaving the now divorced couple free to marry wherever, whenever, and whomever they choose.
The idea of comity developed from the need for unity amid the distinct legal systems that began to develop in respective states or jurisdictions.