What are the 19th-century concepts that are considered to be methods of limited use of force, not a war?
In the nineteenth century, States felt that there need to be some restrictions at least, since any small friction had the capacity to lead a full-fledged war that was not intended by either party. The result of this is the invention of concepts such as pacific blockade, embargo, retaliation, reprisal, intervention, etc. all hinting that these are not war, but methods of limited use of force.