Last October, at an annual meeting of the United States Army Association, two American companies showcased a new version of the "Jackal" missile. The missile is over 1 meter long, and some foreign media have classified it as a small and micro cruise missile. What is a small and micro cruise missile? To answer this question, we need to start with cruise missiles. Cruise missile is a missile that can fly in the dense atmosphere in the most economical way by relying on jet engine thrust and wing aerodynamic lift. Cruise refers to the balance between the thrust and flight resistance of the jet engine and the lift of the wing and the weight of the missile body after launch or deployment, thus achieving a state of uniform speed and altitude flight. The development positioning of cruise missiles is to strike some high-value targets, usually with larger bodies and lengths ranging from 5 to 10 meters. The Russian Kh-55 cruise missile is over 6 meters long and has a body diameter of about 0.5 meters. This size can carry larger warheads, ensuring the destruction of targets. Some anti-ship cruise missiles can completely destroy a large warship with just a few rounds. The changes in the combat environment have led cruise missiles to be used to strike more types of targets, such as rapidly constructed fortifications and larger unmanned ships. Using traditional cruise missiles to attack is clearly not cost-effective enough. Due to the comprehensive consideration of strike effectiveness and cost, some countries have begun to develop "miniaturized" cruise missiles, which are small and micro cruise missiles. The UK Ministry of Defense recently claimed that the "Spear 3" test fired is a small and micro cruise missile. The length of "Spear 3" is about 2 meters, and the diameter of the projectile is 0.18 meters, which is significantly smaller in size compared to traditional cruise missiles. But objectively speaking, the size of this small and micro cruise missile is not small, and the qualifier "small and micro" is more like emphasizing that it is slightly smaller than traditional cruise missiles. From the perspective of "Spear 3", it is "small in size but complete in all five organs". Some components of cruise missiles are almost identical: it is equipped with advanced navigation and guidance systems, including multi-mode guidance heads and bidirectional data links; Equipped with folding wings, the ejected wings during flight generate lift to achieve missile cruising; Use turbojet engines to generate forward thrust at a high speed. In weapon classification, cruise missiles are most easily confused with small and micro cruise missiles, but there are significant differences between the two. These differences are reflected not only in the complexity of the projectile structure, flight speed, range, but also in its usage and lethality. Generally speaking, the structure of small and micro cruise missiles is more complex, with faster flight speed, longer range, greater power, and often greater value in striking targets, and they are usually "never to return". For example, the targets that "Spear 3" can strike include main battle tanks, self-propelled artillery, armored transport vehicles, surface vessels, etc., all of which have a high cost. However, patrol missiles are inferior in the above aspects. Many patrol missiles are driven by electric motors, have slower flight speeds, and have a certain ability to hover in empty space. Of course, with the increasing demand on the battlefield, small and micro cruise missiles are also evolving. Some small and micro cruise missiles, such as the "Jackal" missile, are developed as a multifunctional mission platform. With modular design, they can carry out various tasks by carrying intelligence reconnaissance payloads. Currently, the development of small and micro cruise missiles is accelerating. Especially after unmanned aerial vehicles are deployed in actual combat, there is an urgent need for ammunition suitable for their own carrying and use, and small and micro cruise missiles are one of the options. In recent years, the "Archer" micro cruise missile launched by Türkiye Bekaa Company is designed to be applicable to UAVs. As more countries join the ranks of research and development and use, these small and micro cruise missiles may usher in new changes. (New Society)