This cannot be interpreted otherwise than a serious development as it proves that the U.S. remains unchanged in its scenario for preemptive nuclear attack on the DPRK.

It is against the backdrop of such moves of the U.S. that forces hostile to the DPRK are becoming increasingly assertive for working out extended deterrence strategy in the East Asian region including the Korean Peninsula.

At a recent symposium sponsored by the Carnegie International Peace Foundation of the U.S., a professor of Keio University of Japan said that extended deterrence is part of the U.S nuclear strategy, adding that the redrafting of the plan for extended deterrence by the U.S and south Korea would play an important role in coping with someone's "provocation."

The true colors of a robber can never change.

The U.S. and other warlike forces are playing camouflaged peace tactics. They are strengthening nuclear cooperation under the pretext of the fictitious "threat" from the DPRK, talking about "detente" on the Korean Peninsula.

In this regard, it is worth recalling the remarks made by the U.S. chief executive in Prague in April of 2009 that the U.S. would steadily maintain effective deterrence for itself and its allies.

The U.S. elaborated long ago on the contents of the "extended deterrence" like "nuclear umbrella" and the missile defence system it offered to south Korea and Japan, while talking about "coping with" someone's "nuclear threat."

Through this, the U.S. is retaining a tighter grip on south Korea and Japan as its advance bases for its preemptive nuclear attack and rounding off the preparations for a war of aggression against the DPRK.

The reality compels the DPRK to boost its war deterrence.

It is a legitimate exercise of the right to self-defence, in every aspect, for the DPRK to bolster its war deterrence to protect the supreme interests and security of the country from the reckless moves of the hostile forces for aggression.