North Korea is showing many signs of instability and South Korea, China and the U.S. must start talking about a possible regime collapse, according to a leading U.S. journalist.

In an editorial in the Washington Post on Monday, CNN host Fareed Zakaria warned that "chaos on the Korean peninsula" could trigger competing and hostile reactions from the U.S and China.

Claiming that a meltdown of the North Korean regime is more threatening than Pyongyang's nuclear arsenal, he said serious geopolitical instability is bound to occur unless there is careful preparation among Seoul, Beijing, and Washington.