Step 1: Understand the dispute.
The North Sea Continental Shelf cases involved disputes between Germany and Denmark, and Germany and the Netherlands, over the delimitation of their shared continental shelf.
Denmark and the Netherlands argued for the "equidistance principle" (drawing a line equidistant from both coastlines), which would have given Germany a very small share due to its concave coastline.
Step 2: Know the ICJ's ruling.
The International Court of Justice (ICJ) rejected the argument that the equidistance principle was a mandatory rule of customary international law.
Instead, the Court emphasized that the delimitation should be carried out by agreement and based on equitable principles, taking into account all the relevant circumstances (like the shape of the coastline) to arrive at a fair and just result.