TOKYO -- Once touted as a "friendship cemented in blood," the relations between Beijing and Pyongyang have deteriorated to new lows -- perhaps to a point from which they cannot be salvaged.
The roots of mistrust stem back to the execution of Jang Song Thaek, the uncle of North Korea's leader Kim Jong Un, in 2013, and the rift has intensified as the relationship was intertwined with the power struggles on the Chinese side.
