On January 6, 2016, North Korea announced that it had successfully detonated a “miniaturized hydrogen bomb,” its fourth nuclear test in 10 years.

Thousands of North Koreans gathered in Pyongyang two days later to celebrate with a mass rally and dance in Kim Il Sung Square. That it was also Supreme Leader Kim Jong Un’s 32nd birthday may or may not have been a coincidence; a giant fireworks display exploded overhead.

The rest of the world was less jubilant. The United Nations (UN) Security Council “strongly condemned” the test and promised to impose tough new sanctions on the rogue state.