On Friday morning, North Korea conducted its fifth and most powerful nuclear test to date, marking another step forward in its nuclear weapons program.
Monitoring agencies suspected a nuclear explosion had occurred when they detected seismic waves from an unusual 5.3-magnitude tremor very close to Punggye-ri — an underground nuclear site that has been the location of four previous nuclear tests (2006, 2009, 2013, and, most recently, January 2016).
Hours later, North Korean state media confirmed that it had carried out a “nuclear warhead explosion test.”
The White House swiftly condemned the test as "a grave threat to regional security and international peace" and said President Barack Obama had consulted with the leaders of South Korea and Japan by phone. The White House said the leaders had agreed to work with the UN Security Council to implement the current sanctions against North Korea as well as to impose new ones in response to the test.
UN Secretary General Ban Ki-moon also condemned the test as a “brazen breach” of UN resolutions and urged the Security Council to “unite and take urgent actions.”
According to South Korean officials, the “nuclear yield” of the explosion was 10 kilotons — that means the explosion released the amount of energy equivalent to that released by 10,000 tons of TNT. If confirmed, this would be the most powerful explosion in a North Korean nuclear test ever recorded.
In January, the North Korean regime boasted that it had successfully carried out its first underground test of a hydrogen bomb, a weapon much more powerful than an atomic bomb. Experts have doubted this claim, stating that none of the previous blasts were large enough to have been caused by a hydrogen bomb.
Aside from these nuclear tests, North Korea has been developing a missile program over the past few decades, which has grown from artillery rockets to short- and medium-range ballistic missiles. Last Monday, as G20 leaders were meeting in China, North Korea fired three ballistic missiles into the Sea of Japan.
The country is also investing in the development of long-range missiles, and some of these missiles could hypothetically have the capacity to carry nuclear warheads, as Jeffrey Lewis, director of the East Asia Nonproliferation Program at the Middlebury Institute of International Studies at Monterey, told to Vox’s Zack Beauchamp.
In addition to all these missiles, there are recent reports that North Korea is testing firing ballistic missiles from a submarine. These missiles would be a significant boost to Pyongyang’s arsenal, as they are much more difficult to detect and have a bigger range than land-based ones.