ASEAN

The article talks about the “ASEAN way” and describes this as the most “hallowed” or important part of the way ASEAN works.
This country was barred from the meeting discussed in the article because the military took over the government.
ASEAN was originally formed in 1950 at the height of the Korean War to combat Russian influence in the region.
What four powers make up the “Quad” described in the article?