As I've previously written regarding Iran sanctions avoidance, North Korea appears to be implementing an old technique in a new place to circumvent US sanctions via maritime cargo transfers in the Sea of Japan. Support from Russia and China has continued to embolden North Korea's attempts at expanding their economic activity.

Lack of regional cooperation from other nations are a primary reason that US sanctions efforts sometimes lack the intended effect, and the US government's ability to persuade global powerhouses like China and Russia to enforce OFAC initiatives is inherently limited.