North Korea's claim that it had tested a hydrogen bomb on Wednesday caused concern all around the world. While it was North Korea's fourth test of a nuclear weapon, the use of a hydrogen bomb would suggest a step up from the countries' nuclear program.
However, multiple experts have cast doubt on North Korea's claim that they were testing an h-bomb. Why? Because the explosion it appears to produce was far too weak.
To put it in a historical perspective, the chart below shows how it compares to some of the most powerful nuclear tests from other nations below:
However, this second chart is perhaps a better indication of why this test causes so much concern.
North Korea's nuclear program may be nascent and Pyongyang could well be lying about its capabilities – but North Korea is the only country in the world currently carrying out nuclear tests. It has continued to pursue nuclear weapons, despite considerable international politics and economic pressure.
More on WorldViews