International law does not depend on "enforcement", and certainly not on any hypothetical number called "majority of cases". In fact enforcement is pretty much impossible, due to the fact that all states are sovereign and cannot be forced to act in certain ways. Short of war which for obvious reasons often is a very bad idea or even impossible there is no way to actually try to force another nation to abide by international law. Find me a credible source that supports your notion please, I would prefer it to be a professor of law and not a politician or a blogger...
In Cameroon, suicide bombing toll rises to 19 dead, 143 wounded (Reuters)
from the article: The EU's glaring hypocrisy regarding Israel