"We can come up with a whole list of possibilities, but it's nothing but idle speculation at this point," James Church, a pseudonym used by a former Western intelligence officer, said in a posting. "Maybe what we should actually be doing, if we're serious, is clam up and watch, day by day, what happens."
The official Korean Central News Agency said Jang Song Thaek, the leader's uncle, was executed Friday for treason. Jang earlier this week was ousted as vice chairman of the National Defense Commission and secretary of the Workers' Party of Korea.
John Park, a North Korean expert at Harvard's Kennedy School of Government, told CNN the execution was a sign Kim was culling those loyal to his father and former leader Kim Jong Il, who died in 2011.
Yonhap, the South Korean news agency, reported Jang was a moderate in a North Korean government comprised of hawkish military leaders as well as an advocate of economic reform.
Church said he took interest in the notion that Jang's execution may have something to do with economic reform but said it was far too soon to make any assessments given the rare publicity from North Korean media of the execution and earlier ouster.
"Since we've never seen one of these before, we have no way of knowing how to interpret it," he said.