South Korea never technically made peace with the North, and still remains in a state of war, though major hostilities never resumed after 1953. The U.S. still keeps 28,500 troops in South Korea and guarantees a “nuclear umbrella” in case of an invasion from the north, in exchange for which Seoul agreed to limit the range of its ballistic missiles to 300km (186 mi). But ground-hugging cruise missiles weighing less than 500 kilograms (1,100 pounds) do not fall under that provision, and have been developed to the point of reaching across the continent.

On this day, July 17, in 2010, South Korea’s Defense Development Agency announced they were starting production on the Hyunmu-3C missile, capable of flying 1,500 kilometers (937 miles). The previous missile they had only flew for 1,000 kilometers.

For South Korea, the move was a necessary response to the many North Korean missiles aimed at them. North Korea twice tested the Taepodong-2 intercontinental missile which has a potential range of more than 4,100 miles — enough even to put Alaska within striking distance.