Anonymous reports that now we are going to experience the most revolutionary change in US alliance relations in Northeast Asia since the Korean War.
According to the most influential Japanese commentator on Korean matters, Takabumi Suzuoki [1], in the near future, the US and South Korean (SK) alliance will be eliminated [2]. The geopolitical structure of the "red team" (China/Russia/North Korea (NK)) vs the "blue team" (US/Japan/SK) might change to China/Russia/Unified K vs US/Japan. The current border confrontation of the red and blue teams along the 38th parallel might shift to the Sea of Japan (the New Acheson Line).
"SK is secretly establishing a nuclear propelled submarine and is going to equip it with nuclear missiles from NK. Such a situation is a nightmare for the blue team, but it is possible."
[1] Suzuoki predicted the eventual elimination of the US-SK alliance years ago. Many predictions by Suzuoki have been realized.
[2] The SK President, Moon Jae-inn, and Trump are expecting the elimination of the SK-US alliance. The recent withdrawal of SK from the SK-Japan intelligence sharing agreement, known as "General Security of Military Information Agreement (GSOMIA)" is one of the signs of the crumbling US-SK alliance.
Pete Comment
Trump's policy of bilateral talks with NK's Kim Jung-on, with minimal US confidential or publically demonstrated consultation with SK, has shaken SK.
SK's fear of growing (near-neighbour) Chinese economic and military power has led to SK efforts to strengthen relations with China. This has been at the expense of SK relations with the US.
Trade disputes between the US and SK also have increased tension. Additionally the Trump induced US-China trade dispute has impacted the SK economy and SK strategic confidence.