The country’s weapons are likely more advanced and dangerous than many experts think. 
The estimated yield for North Korea’s fifth nuclear test, in September 2016, is between 20 and 30 kilotons.
Feb. 28.─ North Korea successfully tested a solid-fueled missile earlier this month, the latest in a series of technological leaps. Instant experts allege Pyongyang is not yet a serious nuclear threat to the U.S. Some reporters say North Korea does not have “miniaturized” nuclear warheads for missile delivery and that its weapons are primitive—even after five nuclear tests. These are dangerous delusions.
Google the history of nuclear testing and weapons development, and North Korea’s tests suddenly seem a lot more serious. This has all been done by the U.S., the Soviet Union, China, Britain, France, Israel, South Africa, India and Pakistan. History suggests North Korea already has nuclear-missile warheads and a sophisticated array of nuclear weapons.
Testing is not necessary to develop nuclear weapons. The first atomic bomb, which used enriched uranium, was never tested: Hiroshima was the test. The second one, which used plutonium, was tested once and worked perfectly at Trinity and on Nagasaki. 
France entered the nuclear club in 1960 with a sophisticated high-yield fission weapon that worked perfectly on its first test ...