Which international routes might save fuel and time by using a potential newly "deemed safe" North Korean air space? The Reuters News item Exclusive: U.S. blocks North Korean air traffic revival ahead of Trump-Kim summit - sources says:


  If the space was deemed safe, international airlines could save fuel and time on some routes between Asia and Europe and North America, and North Korea could begin reviving its own commercial aviation industry.


Question: Which international routes in particular, flown by international airlines could save fuel and time on some routes between Asia and Europe and North America by using newly "deemed safe" North Korean air space?
I think the biggest one would be Tokyo - Beijing, and more broadly, anything in Japan north of Osaka to Beijing.



The current airway turns does a dogleg up to right above Incheon airport, (you can literally see the airport and Seoul).

You can play with http://www.gcmap.com to see great circle maps, which are a good approximation of the most efficient route.