Gene editing technologies, such as CRISPR-Cas9, have the potential to modify the DNA of organisms and can theoretically be used to change the behavioral characteristics of animals. However, for a variety of reasons, the use of such technologies to enhance the aggressiveness of animals for military purposes poses many ethical, scientific and practical challenges. 1. **Ethical issues**: Manipulating animal behavior for military purposes involves serious ethical controversies. This involves issues such as animal welfare, ecological impacts and human responsibility. 2. **Scientific challenges**: Animal behavior is often determined by complex multi-gene networks and environmental factors. Simply editing a gene may not achieve the desired behavioral changes, but may instead trigger unpredictable side effects. 3. **Ecological and environmental impacts**: Changing the behavior of certain animals may have unpredictable effects on the balance of ecosystems and may lead to damage to biodiversity. 4. **Control and safety**: Even if the aggressiveness of an animal can be enhanced, how to effectively control and deploy these animals to avoid uncontrolled attacks remains a major challenge. 5. **International regulations and agreements**: In terms of biological weapons, there are many international treaties and agreements, such as the Biological Weapons Convention, which prohibit the use of biotechnology to develop offensive and destructive weapons. Therefore, although there may be some possibility in technology, it will still face many obstacles and widespread international condemnation in its actual application. Currently, gene editing technology is more used for peaceful purposes such as medicine, agriculture and biological research.