Missile Dongfeng DF-21 / CSS-5

The Dongfeng 21 (DF-21), designated CSS-5 by NATO, is a two-stage, solid-fuel medium-range ballistic missile. Its development commenced in the late 1960s, with completion occurring around 1985–86, and operational deployment beginning in 1991. The missile was derived from a submarine-launched missile, marking it as China's first solid-fuel land-based missile.

Originally conceived as a strategic weapon, later variants of the DF-21 were designed for both nuclear and conventional missions. For strategic strikes, it is capable of carrying a nuclear warhead, with reported yields ranging from 200 to 500 kt. Conventional options include a high explosive or submunition payload, intended for tactical or theater-level operations. The DF-21C variant incorporates terminal guidance, distinguishing itself as the first dual-capable version adaptable for either nuclear or conventional warheads. The most recent iteration, the DF-21D, is notably the world's first anti-ship ballistic missile (ASBM), employing maneuverable reentry vehicles with a terminal guidance system designed to engage moving naval targets, utilizing satellite and radar support for targeting. Furthermore, the DF-21 platform has been adapted for space warfare roles, including anti-satellite and anti-missile weapon applications.

The DF-21 entered service in 1991 and is utilized by the People's Liberation Army Rocket Force and has also been exported to the Royal Saudi Strategic Missile Force. While employing a mobile launcher to enhance survivability, its operational deployment requires support vehicles that encompass a substantial area, limiting rapid movement and restricting firing locations to roads or prepared pads due to its hard launch system. The DF-21C was being deployed in central Western China by 2010. Noteworthy public demonstrations and tests include an apparent test against a mock aircraft carrier in the Gobi Desert in January 2013 and a launch into the South China Sea in August 2020. The acquisition of DF-21 missiles by Saudi Arabia reportedly occurred around 2007, under the condition that the missiles were conventionally armed.