Already back in 1950 the then U.S. President Truman openly talked about the use of A-bomb on Korean fronts. According to it, an instruction was issued to the U.S. strategic flying corps to "be on standby to be able to send bombers to the Far East for the immediate delivery of A-bombs."

The then commander of the U.S. forces in the Far East MacArthur blustered that they would form radioactivity corridor in the northern part of Korea linking the east sea and the west sea i, adding that no living thing will be able to come back to life in the zone in 60 or 120 years.

In 1953 the U.S. strategic air force command worked out OPLAN 8-53 calling for dropping huge A-bombs from the air on the DPRK and China. In 1954 a strategic meeting was held with the attendance of high-ranking officials of the U.S. State Department, Defense Department, the Joint Chiefs of Staff, CIA and the three services of its armed forces in which they drafted an operational plan envisaging an attack by A-bomb in case of "contingency" on the Korean Peninsula.

The U.S. brought its armored division to south Korea from Japan in 1957 and combined it with the U.S. 24th Division into an "atomic division" and in the year that followed it made public the deployment of Honest John and 280 mm atomic artillery pieces in south Korea.

It built new nuclear arsenals or expanded them in different parts of south Korea all the while systematically introducing nuclear weapons there. They put on a high alert even those units in charge of storing nuclear bombs and supplying equipment to get them gird for a nuclear war anytime.

The U.S. deployed at least 1 720 tactical nuclear weapons with diverse missions in south Korea till 1991. Their deployment in south Korea was four times as dense as those weapons deployed in NATO areas at the time of 1990.

In 1992 the U.S. stated to the public that it "withdrew all tactical nuclear weapons" from south Korea but the U.S. policy for making south Korea its nuclear base has not changed even a bit.

In 1997 the U.S. openly transferred uranium shells to south Korea from the U.S. military base in Okinawa, Japan.

At the 41st U.S.-south Korea annual security consultative meeting in 2009 the U.S. specified the U.S. provision of a "nuclear umbrella" to south Korea, which "had just been declared," as an "extended deterrence" that envisaged attacking the rival in the same way as when the U.S. mainland came under a nuclear attack. This paved a way for bringing huge more nuclear weapons to south Korea any moment.

The U.S. put the DPRK in the list of preemptive nuclear attacks in the "nuclear posture review" and even worked out a war document which called for the use of nuclear weapons against the DPRK in case of "contingency".

The U.S. staged Freedom Bolt, Team Spirit, Key Resolve, Foal Eagle, Ulji Freedom Guardian and other mad-cap nuclear war rehearsals to invade the DPRK for the last several decades.

All facts prove that the U.S. nuclear threats and blackmail against the DPRK that date back to the1950s still continue.

It is the legitimate exercise of the right to self-defence for the DPRK to continue bolstering nuclear capabilities as long as the U.S. policy of nuclear blackmail continues.

The DPRK's nuclear deterrence will become further modernized and expanded unless the U.S. drops its policy of nuclear blackmail against the DPRK.