It was recently revealed that on March 31st, as South Korea implemented new (since 2010) war plans in the face of another North Korea attack, several South Korean F-15K fighter bombers took off armed with SLAM-ER missiles and headed for the North Korean border. This apparently alarmed the North Koreans a great deal, as did the overall rapidity of the South Korean response to North Korean coastal artillery firing some shells into South Korean coastal waters. An F-15K equipped with SLAM-ER can destroy any ship in the North Korean navy as well as a wide variety of land targets. North Korean defenses are largely ineffective against the F-15K and the SLAM-ER. The F-15K has also been seen carrying the GBU-28, a smart bomb designed to penetrate the ground and destroy the many underground bunkers the North Korean commanders operate from in wartime.
The F-15K is an upgraded version of the 36 ton U.S. F-15E (a two seat fighter bomber version of the single seat, 31 ton F-15C fighter). In service since 1988, the F-15E can carry up to 11 tons of bombs and missiles, along with a targeting pod and an internal 20mm cannon. The first F-15Ks were ordered in 2002 and delivery was completed in 2012. The South Korean Air Force wanted 120 F-15Ks but there was only money available to buy 61 of the $100 million aircraft.
The AGM-84K SLAM-ER (Standoff Land Attack Missile - Expanded Response) began full-rate production in 2000. This is a 675 kg (1,487 pound) cruise missile with a range of 270 kilometers, a speed of 855 kilometers an hour and GPS/shape recognition guidance system that is very accurate. Moreover the target can be changed or mission aborted by the pilot at any time. SLAM-ER costs about $500,000 each and has a 220 kg (500 pound) warhead based on the one used on the Tomahawk cruise missile. SLAM-ER is actually a scaled up Harpoon anti-ship missile. The U.S. Navy has about 700 of them while South Korea bought over a hundred.