Back in 2009 Taiwan announced that it would build its own long range gliding smart bomb, something similar to the U.S. JSOW-ER. In January 2014 this weapon entered service and was shown mounted under the wing of a Taiwanese jet fighter. Taiwan tried to buy JSOW from 2006 to 2009 but the U.S., bullied and manipulated by China, refused to sell. The Americans said they did not want to sell Taiwan aircraft weapons that could be used to attack China. In particular, this meant no radar homing (AGM-88C HARM) missiles and JDAM smart bombs. To get around this policy Taiwan began developing its own smart bombs, particularly something similar to the American JSOW (Joint Stand Off Weapon) Also called the AGM-154A, the Taiwanese version is called the Wan Chien. Taiwan also went ahead and built its own version of JDAM.
Normally, JSOW is unpowered but able to glide for up to 22-130 kilometers (depending on the altitude it is dropped from). The powered version (JSOW-ER) has a range of 500 kilometers. The Taiwanese version is more compact and has a range of 200 kilometers. The original unpowered JSOW entered service in the late 1990s, and Australia, Canada, Greece, Finland, Poland, Singapore, Turkey, and the Netherlands have bought small quantities. The U.S. Navy and Air Force have bought over a thousand and used 400 in the Balkans, Iraq, and Afghanistan.
JSOW is basically a smart bomb with wings. That enables it to glide from the aircraft dropping it to a target on the ground. Range is about 25 kilometers if dropped from low altitude. JSOW also contains more elaborate fins and software that enables it to follow a specific route. Like the wingless JDAM smart bomb, JSOW uses GPS and inertial guidance (as a backup) to find its target. Like JDAM, JSOW hits within 10 meters (33 feet) of its aiming point. The U.S. pays about $250,000 for each JSOW. The Taiwanese plan to use their Wan Chien JSOW as a form of HARM to take out the latest Chinese air defense radars, by adding additional sensors to the guidance system.
Taiwan also built its own version of HARM, called Tien Chien 2A. JDAM technology is a lot simpler than HARM or JSOW and Taiwan went ahead built its own. Refusing to sell them just costs the U.S. export sales. On the other hand, it allows the United States to tell China that it didn't sell JDAM to Taiwan, thus defusing tensions over Taiwan. In reality, of course, Taiwan just built their own JDAM.
JDAM (Joint Direct Attack Munitions, or GPS satellite guided bombs) were developed in the U.S. in the 1990s, shortly after the GPS network went live. In 1991, the GPS system was just coming into service. There were already plans for something like JDAM, but no one was sure that it would work. Once the engineers got onto it, it was discovered that JDAM not only worked, but cost less than half as much to build ($18,000 per bomb) as the air force expected ($40,000 a bomb). The current price is still under $30,000 each.
JDAM was a "kit" that attached little movable wings, along with batteries and a GPS guidance unit, to a normal "dumb" bomb. This enabled the JDAM to hit a target with great precision. The technology was off-the-shelf, so the Taiwanese had no problems developing and building their own.
In 1996, production of U.S. JDAM began. The bombs got their first workout in the 1999 Kosovo campaign. To everyone's surprise, 98 percent of the 652 JDAMs used, hit their targets. In 2001, JDAM proved the ideal weapon for supporting the few hundred Special Forces and CIA personnel the U.S. had on the ground in Afghanistan. The JDAM was more accurate, and effective, than anticipated. By January, 2002, the U.S. had dropped about half their inventory, of 10,000 JDAMs, in Afghanistan.