SEOUL — North Korea fired two short-range ballistic missiles Monday morning in what it quickly made clear was retaliation for joint US-South Korean air exercises involving a pair of B-1B strategic bombers. and F-35 stealth fighters hours earlier. A lightning-quick statement in the official Korean Central News Agency said a simulated multiple-rocket launch from the western front had aimed two 600-millimeter rockets at targets 395 kilometers and 337 kilometers to the east. The statement boasted that just four rounds of the rockets, which it characterized as capable of delivering a tactical nuclear weapon, could devastate an airfield. South Korea’s Joint Chiefs of Staff said it detected two short-range ballistic missiles fired between 7 a.m. and 6 p.m. m. and 7:11 a.m. m. from the North Korean area of Sukchon, north of the capital Pyongyang, into waters east of the Korean peninsula. The weapons’ flight distance, up to 390 kilometers as quoted by the Seoul military, if placed at a different angle could theoretically place multiple airbases in South Korea within range, including US Air Force bases. in Osan and Gunsan. Also read UN: North Korean hackers steal record virtual assets