Taiwan's air force makes extensive use of domestic air to air missile platform, the Sky Sword, which are seeing their usage expanded and being increasingly adapted to counter new Chinese fighters. The Sky Sword II air to air missile has a range of up to 100km and allegedly is able to surpass Mach 5. It compares favourably to the U.S. AIM-120B used by American fourth generation fighters, the range of which is restricted to just 75km. Taiwan's military hopes that the missiles can do something to negate Beijing's overwhelming advantage in the air, which is primarily technological but also numerical. Among other measures, Taiwan's domestic fighter the Ching Kuo is being modified to carry four instead of two of the formidable air to air missiles. Taiwan's Navy is also set to receive a surface to air based variant of the Sky Sword II to be deployed from its Lafayette frigates from 2020 - a modernisation process expected to be complete by 2028.
Formidable though it may be, much like Taiwan's other recent modernisation initiatives the Sky Sword's impact on a future defensive conflict with the Chinese mainland would be negligible. While Taiwan's fighters will double their payloads to carry four Sky Sword II missiles each - Taiwan's entire fleet of is comprised of light multirole fighters - the Ching Kuo, F-16 and Mirage 2000 all being roughly comparable in their capabilities and fulfilling the same role - equivalent to China's J-10. Against China's heavy dedicated air superiority platforms however, of which the country fields hundreds, the Taiwanese aircraft will stand little chance. While the Ching Kuo can carry four missiles, the Su-35 in Beijing's service can carry fourteen. These platforms are not only longer ranged, faster, better armed and more manoeuvrable, but they also carry missiles with ranges superior to those of the Sky Sword and far superior radars with which to acquire enemy targets. The R-27 for example has a maximum range of 130km, allowing Chinese J-11, Su-30 and other heavy fighters to comfortably pick off Taiwanese platforms at range - even if the latter can coordinate with AWACS to compensate for their relatively poor radars. If reports of China receiving Russian MiG-31 fighters and R-33 missiles are true - this will increase to over 300km, allowing Chinese interceptors to shoot fighters over Taiwan like fish in a barrel well beyond not just firing range but also detection range. Close range, engagements between Taiwan's F-16 type fighters and China's Su-27 variants would be even more one sided - with the latter being in the league of the American F-15 Eagle against which Taiwan lacks countermeasures - having itself failed to acquire the F-15 or F-22.
The superiority Chinese technology, admittedly largely Russian derived, will enjoy in the air over Taiwan's by comparison meagre Air Force fails to even mention China's two greatest assets in claiming air superiority over the territory. The first is the Chengdu J-20, China's equivalent to the F-22 Raptor, which by the time the Sky Sword II is fully integrated in the Taiwanese military will be in service in the hundreds. This will be able to evade Taiwan's long range radars and neutralise its fighters - seemingly coming out of nowhere - with Taipei showing no signs of developing sophisticated anti stealth technologies as of yet.
Perhaps China's greatest asset in contending Taiwanese airspace however, one which could potentially ground the Taiwanese Air Force near instantly should a war break out, are the country's S-400 long range surface to air missile batteries. With a range of 400km covering all of Taiwan's airspace, complemented by the S-300 which covers the entire northern half, Taiwanese fighters would be at risk the moment they take off of being fired on what is widely considered among both Russian and Western allies to be the world's most advanced air defence system. Made to target radar evading platforms such as the F-22, against the F-16 and similar platforms fielded by Taiwan the S-400 will be overkill.
Taiwan's modernisations could in different circumstances make meaningful enhancements to its military. As it is however the vast majority of the country's Air Force may well never get in range to use its new missiles, and could likely find itself grounded from the outset of a large scale war with the mainland. Unless Taiwan makes some major new acquisitions, notably not of any platform the U.S. has been willing to sell, such as its own air superiority fighters or advanced SAM systems similar to the S-300, the country will remain vulnerable to losing air superiority near instantly should China decide to press an attack.