The idea of genetically modifying animals to make them more aggressive and use them for military purposes is theoretically feasible, but there are many technical, ethical and legal challenges in practice. 1. **Technical Challenges**: Genetic modification technologies, such as CRISPR-Cas9, can edit specific genes, but in terms of achieving the desired traits and behaviors, the behavior of animals is affected by multiple genes and environmental factors, which is far more complex than a single gene. Therefore, it is challenging to ensure that animals achieve the desired effect on aggression and maintain other necessary physiological functions. 2. **Ethical Issues**: Modifying animals to be more aggressive and use them for military purposes involves major ethical issues. Many countries and organizations have strict animal welfare laws and regulations on this, emphasizing the humane treatment of animals. The use of modified animals for military purposes may cause widespread ethical controversy. 3. **Laws and Regulations**: At the international and domestic law levels, relevant laws on biological weapons and animal rights may also restrict such research and applications. For example, the Biological Weapons Convention prohibits the development and production of biological weapons, including animals. 4. **Consequences and Risks**: Even if it is technically feasible, the humanitarian crisis, ecological imbalance and potential biosafety risks are also important considerations. In general, although the development of genetic modification technology has made certain theoretical possibilities exist, the difficulties and risks faced in practical applications make this approach unlikely to be realized in the short term.