The intermediate ballistic missile launch over Hokkaido was, again, clearly in coordination with China. U.S. and SK are currently conducting their annual joint military exercises. China has repeatedly stated that the military exercises are a "provocation" and wants them to end. Likewise, the U.S. military presence outside of the Continental U.S. is a "provocation." NK's missile technology, components, and infrastructure are all courtesy of China. China receives 80-90% of NK's exports. KJU doesn't hit the head without phoning Beijing. 

NK has fired approximately 80 missiles since KJU took power. 4 of their successful nuclear tests came in the past 8 years. China is using NK as just another arrow to fire at the U.S., SK, and Japan. China wants to cleave away our military relationships with both countries. China's pan-Asian hegemony is premised on NK threats to yield U.S. military concessions. What's more provocative than firing a missile over Japan? Firing 4 at Guam. Stay tuned.