The DF-21/21A (CSS-5) solid-fueled missile was originally developed as the two-stage JL-1. It was designed for deployment aboard China's SSBN, and it was decided to also develop it as a land-based missile, which was designated as the DF-21. Development of the DF-21 began in 1967 and
had its first successful test in May 1985. Shortly thereafter, the
DF-21 was deployed into an experimental regiment. Its range was later improved to 1800 kms (DF-21A) carrying a 600 kg warhead with a nuclear capability believed to be 200-300 kt. This mobile system is launched from a transporter-erector-launcher (TEL) vehicle.
It is believed that over 100 DF-21/JL-1 missiles have been built, and as of 1995 some 15 to 20 DF-21 missiles had been deployed, with deployments increasing to some 36 by 1997. Some DF-21s have been reconfigured with conventional warheads for use along China's southern and northwestern borders. From these locations, the DF-21 can hit targets throughout Northern India, the Republics of Central Asia, and most of Vietnam and Southeast Asia. As of late 1997 China had about 40 DF-3 re fire-capable launchers at six field garrisons and launch complexes. Many of those launchers are being converted to handle new, solid-fuel DF-21 [CSS-5 Mod 1] launchers and missiles.
A 1997 report by the Air Force National Air Intelligence Center stated that the CSS-5 was being deployed in Chinese border areas to provide coverage of Russia, Central Asian, India, Japan, Korea, and the Philippines. The CSS-5 and CSS-2s are deployed at Tonghua, near North Korea; at Lianxiwang, near Taiwan; at Jianshui, near the China-Vietnam border; and at Datong in central China.
The number of CSS-2 sites will likely be reduced, since the United States no longer operates bases in the Philippines, and DF-15 [M-9] short-range missiles deployed along the eastern coast can be used to cover targets in Taiwan. The DF-21 deployments have been limited to areas closer to China's borders to ensure adequate target coverage of areas previously covered by the DF-3. In areas deeper inside China, where longer range is necessary for target coverage, DF-3 activities are relatively high, indicating the missile could remain in service in these regions until new missiles such as the DF-21 [CSS-5 Mod 2] are deployed. Once the DF-21 deployments are adequately under way, the CSS-2 will likely be removed completely from service, perhaps by 2002.
The July 2000 Japan white paper on defense stated that China had 70 guided missiles capable of reaching Japan and other Asian countries. The white paper noted that China has been gradually replacing the old DF-3 missiles with the newer, more accurate DF-21 missiles.
The Taipei Times reported on 15 July 2002 that China had test-launched two CSS-5 missiles from mobile launchers in Jiangxi province, in south-central China, to target sites in Gansu province in the northwest. In early July 2002 test-fired a CSS-5 medium-range missile with six or seven dummy warhead penetration aids designed to defeat missile defenses. The launch of the missile was conducted from a missile base in southern China. The CSS-5 was tracked from the test site to an impact range in western China after a flight of about 1,300 miles. The missile is believed to be a more advanced version of the CSS-5, known as a Mod 2.
Work is believed to be ongoing to provide this missile with a sophisticated terminal guidance system. According to some reports the Mod 2 version of the CSS-5 will be comparable to the US Perishing II IRBM, employ advanced radar guidance to achieve extremely high accuracy. In 2009 the US Defense Department reported that analyses of current and projected force structure improvements suggested that China was seeking the capacity to hold surface ships at risk through a layered capability reaching out to the "second island chain." One area of investment involves combining conventionally-armed anti-ship ballistic missiles (ASBMs) based on the CSS-5 (DF-21) airframe, C4ISR for geo-location and tracking of targets, and onboard guidance systems for terminal homing to strike surface ships. As described in an authoritative 2004 article for the Second Artillery Corps, the ASBM could employ "terminal-sensitive penetrating sub-munitions" to "destroy the enemy's carrier-borne planes, the control tower and other easily damaged and vital positions." This capability would have particular significance, as it would provide China with preemptive and coercive options in a regional crisis.
China is developing an ASBM based on a variant of the CSS-5 MRBM as a part of its anti-access strategy. The missile has a range in excess of 1,500 km, is armed with a maneuverable warhead, and when incorporated into a sophisticated command and control system, is intended to provide the PLA the capability to attack ships at sea, including aircraft carriers in the western Pacific Ocean.
Beijing retaliated in 2017 to US President Donald Trumpís communication with Taiwan by testing ten DF-21 missiles, which have a reported range of at least 900 miles. Chinese news agency Xinhua wrote that DF-21-class missiles can "destroy US Asia Pacific bases at any time." Military expert Rick Fisher told the Washington Free Beacon that "the PLA is banging some drums to provide background for military psychological warfare."
Its DF-21C is believed to be a derivation on the DF-21/DF-25 for the so called SC-19/KS-19 ASAT ground based system. This is a land variant with improved range capability DF-21. This is the first time this DF-21C has been fully displayed publicly in the practice parade of September 6th for the October 1, 2009, 60th. anniversary parade. More recently it has been credited as a part of a developing (ASBM) Anti Ship Ballistic Missile System according to open source intelligence information and official comments. It is also in part now being potentially associated with the ABM capability known as SC-19 as a derivation of the DF-31 derived KT-1.