In a recent development, North Korea has declared that it has carried out a test of an “underwater nuclear weapons system.” This announcement comes amidst escalating tensions on the Korean Peninsula. What Happened: The state-run Korean Central News Agency (KCNA) reported on Friday that the test was a response to joint military exercises conducted by the United States, South Korea, and Japan, which North Korea perceives as a serious threat to its security, reported The Washington Post. The test involved the “Haeil 5-23” system, a new model of the unmanned, nuclear-capable underwater attack dron…