The 21st century is expected to see the development and emergence of a number of new defence technologies, reflecting the evolving nature of security challenges and the rapid pace of technological advancement.

Some of the key highlights include:
- Directed Energy Weapons (DEWs): DEWs are weapons that use energy to damage or destroy a target, such as lasers or microwaves. These weapons have the potential to be highly precise and have a low collateral damage. DEWs are expected to be used for a variety of applications, including missile defence, air defence, and ground-based defence.
- Cyber defence technologies: Cyber defence technologies are expected to play an increasingly important role in the 21st century as cyber warfare becomes an increasingly significant form of conflict. These technologies include firewalls, intrusion detection systems, and encryption. Additionally, Artificial Intelligence and Machine Learning are expected to be used to enhance the capabilities of these systems and improve their ability to detect and respond to cyber threats.
- Autonomous systems: Autonomous systems, such as drones and robots, are expected to become increasingly important in the 21st century as they can be used for a variety of tasks, including reconnaissance, surveillance, and strike missions, as well as for logistics and other support functions. Advancements in Artificial Intelligence and Machine Learning will allow these systems to operate more independently and make more complex decisions.
- Quantum technologies: Quantum technologies, such as quantum computing and quantum communications, are expected to become increasingly important in the 21st century. These technologies have the potential to greatly enhance the capabilities of defence systems, particularly in areas such as encryption and communication security.
- Hypersonic weapons: Hypersonic weapons, which are capable of traveling at high speeds and at a very low altitude, are expected to become increasingly important in the 21st century. These weapons can be used for a variety of applications, including missile defence and strike missions, and can be highly difficult to detect and intercept.

- Biotechnology: Biotechnology is expected to play an increasingly important role in the 21st century defence industry, particularly in areas such as medicine and logistics. Biotechnology can be used to create new drugs, vaccines, and medical treatments to protect soldiers from diseases, and to create new materials and equipment that are lightweight, durable, and energy-efficient.
- Virtual and Augmented Reality (VR/AR): VR/AR technologies are expected to play an increasingly important role in the 21st century defence industry, particularly in areas such as training, simulation, and command and control. VR/AR can be used to create virtual training environments, allowing soldiers to train in realistic and immersive scenarios.
- Nuclear Fusion technology: Nuclear Fusion technology is expected to play an increasingly important role in the 21st century defence industry, particularly in areas such as energy production, propulsion and power generation. Nuclear Fusion can be used to create new energy sources that are cleaner, more efficient and more powerful.
- Smart materials: Smart materials, such as shape-memory alloys and smart polymers, are expected to play an increasingly important role in the 21st century defence industry. These materials have the ability to change shape, size, and properties in response to changes in temperature, pressure, and other environmental factors, making them ideal for use in weapons systems, vehicles, and other equipment.
- 3D printing: 3D printing technology is expected to play an increasingly important role in the 21st century defence industry, particularly in areas such as logistics, maintenance, and production. 3D printing can be used to create new components and spare parts on-demand, reducing the need to stock and transport large inventories.

Other technologies, such as blockchain, 5G communication networks, and energy storage solutions, may also play an important role in the defence industry in the future.
It’s also important to note that the development and adoption of new defence technologies can have a significant impact on the balance of power and the nature of warfare. For example, new technologies such as hypersonic weapons and autonomous systems may give countries a significant military advantage, while new technologies such as cyber defence systems may be necessary to defend against new types of threats. As such, the development and adoption of new defence technologies will likely be a key area of competition and cooperation among countries in the 21st century.
In conclusion, the 21st century is expected to see the development and emergence of a number of new defence technologies, reflecting the evolving nature of security challenges and the rapid pace of technological advancement. From Directed Energy Weapons and Cyber defence technologies to Autonomous systems and Quantum technologies, these new technologies will play an important role in shaping the defence industry and the way wars are fought. It’s important for countries to stay informed and actively engage with the development and implementation of these new technologies to ensure that they are able to meet the security challenges of the 21st century.