Genetic Engineering and its Application to Warfare

As summarised by the NHGRI, genetic engineering is the process of altering and manipulating the genetic makeup of an organism. It involves the transfer of genes from one organism into another in order to achieve a desired effect such as the new organism expressing a certain trait [National Human Genome Research Institute 2019]^[1]. Foreign DNA can currently be constructed and introduced into organisms by two main methods; recombinant DNA [Burke, Derek 1999]^[2] and gene synthesis [Cunningham, Marcus A., and John P. Geis II., 2020]^[3]. Genetic engineering has far reaching implications for the modern world with applications in medicine, research, industry and agriculture [LibreTexts Biology, Accessed November 14 2025]^[4]. However, the ability to genetically modify organisms creates a dual use dilemma as it comes with significant concerns for global security due to the development of bio-terrorism and genetically modified soldiers. As a result, the uses of genetic engineering in warfare will be explored in this essay.

Recombinant DNA and Gene synthesis

Recombinant DNA technology was first successfully deployed in 1973 by American biochemists  Stanley N. Cohen and Herbert W. Boyer, when they successfully implanted foreign DNA into a bacterial cell. Recombinant DNA is a technique where restriction enzymes are utilized in order to separate target genes from a cell's DNA and to cleave plasmids which results in the generation of two “sticky ends” where the target gene can bind to. Ligase is then used to covalently bond the gene to the plasmid which forms a recombinant plasmid as it takes in the foreign genetic material, this new plasmid is then inserted into a host bacterial cell through a process called transformation [Editors of Britannica, n.d]^[5].

In contrast, gene synthesis can be used to account for the limitations of recombinant DNA techniques. For example, gene synthesis involves the use of oligonucleotides to synthesise entire sequences de novo using computer software and produced by specialised companies. The sequence is then replicated using recombinant DNA techniques [GenScript, 2024]^[6]. The complexity of this phosphoramidite process is outside the scope of this paper (see Fig 5.). The design flexibility in this process allows for greater capabilities in the field of genetic engineering while reducing the dependency on natural DNA.

Biological enhancement through genetic engineering

Through the use of genetic engineering, certain phenotypic traits can be artificially expressed. Simpler non-multigenic traits can often be “knocked out” through the use of CRISPR preventing their function. The effect of this can be preventing the control of something such as muscle growth which is already employed as a therapeutic approach to combatting muscle-wasting disorders. Additionally, CRISPR can be used to replace genes with new ones such as sequences derived from recombinant DNA techniques or artificial ones from gene synthesis. Due to this, sequences that provide a more desirable or efficient function can be inserted into any organism. [Elrashy I, Mohamed et al. 2025]^[7]. However, when discussing the modification of alleles it must be noted that phenotypes are not usually controlled by a single gene, as most human traits are polygenic or influenced by the environment, so it may be difficult to generalise the effects of a phenotype to one specific gene. 

The applications of biological enhancement to warfare

The usefulness of genetic engineering in warfare falls under two main categories; biological enhancement of personnel and biological weapons. 

Personnel enhancement:

Soldiers in specific are the primary target for genetic enhancement due to the physical demands of their role in warfare. Utilising genetic engineering could provide a major advantage over enemy combatants and the gamut of its applications is unprecedented. As there are so many possible uses, only a select few will be discussed; LRP5, MSTN, SCN9A, GRM1 and NR3C1. Before we discuss these genes, it is important to note that for desirable phenotype expression more than one gene may have to be altered to achieve proper functionality. For example, in LRP5 modification the SOST gene may have to be altered simultaneously as they work in the same system. Additionally, environmental circumstances must be considered.

To begin, LRP5 is a gene responsible for a few functions; however, the main point of interest is its role in maintaining and regulating bone density [MedlinePlus, n.d.]^[8]. Genetic mutations in the LRP5 gene have been shown to express undesirable phenotypic effects such as osteoporosis which is a reduction in bone density [Rocca, Santa Maria et al. 2021]^[9]. In spite of this, a genetic mutation which leads to an increase in function also exists which causes conditions such as autosomal dominant osteopetrosis type 1 which induces an increase in bone density [MedlinePlus, n.d.]^[10]. While the negative effects of these mutations are prominent such as hearing loss or chronic pain, the increase in bone density increases the resistance of that individual to blunt force trauma. For example, a 41 year old patient afflicted with the disease was reported to have damaged surgical equipment due to the density of her bones [Jafri SM, Burke EA et al., 2022]^[11]. Natural mutations leading to a gain of function are often too severe for efficient exploitation as represented by the symptom’s high morbidity such as chronic bone pain and disorders of the cranial nerve [Orphanet, 2010]^[12] making the mutation especially unsuitable for warfare. However, with genetic engineering a synthetic gene construct could be produced which has only a slight gain of function to achieve increased bone density while possibly avoiding the symptoms. In theory, such modifications could cause unique resistance to blunt force trauma allowing soldiers to survive blunt force injuries which may have taken others out of action.

Similarly, the MSTN gene can be genetically altered in order to promote skeletal muscle growth by disabling its inhibitory function. MSTN is responsible for the regulation of skeletal muscle growth by binding to certain cells in order to prevent further growth [Gene Cards, 2025]^[13]. Animal testing using genetic constructs of MSTN has already been carried out. For example, the effect on pigs with a modified allele has been studied with the researchers finding that individual muscle mass increased by 100% over the control group counterpart [Qian Lili, Maoxue Tang et al., 2015]^[14]. These findings are useful in predicting the plausibility of similar genetic modification in humans, specifically soldiers in regards to warfare applications. However, the results from animal trials do not always translate into humans so this data must be carefully evaluated. Despite this, there is a strong and well-established positive correlation between muscle mass and muscular strength, [Mya Care Editorial Team, 2023]^[15] allowing for muscle contractions which produce greater force. This theoretically could allow soldiers to increase their speed and the amount of gear they can carry as a few examples amongst the many applications of this modified allele. 

In contrast to this, modification of non-physical attributes are actively being explored through the SCN9A gene. The SCN9A gene is responsible for coding voltage-gated sodium channels [National Center for Biotechnology Information, 2025]^[16] which play significant roles in nociception signaling. Nociception signaling is the process of converting potentially harmful mechanical, chemical or thermal stimulus into electrical signals to be processed as “pain” [Nikolenko VN et al., 2022]^[17]. Therefore, by altering the SCN9A gene, high levels of pain resistance could be expressed. Natural examples of mutations in this gene exist, such as channelopathy-associated insensitivity to pain, in which patients are born without the ability to perceive pain [MedGen, n.d.]^[18]. These natural mutations present traits which are too extreme for utilisation equivalently shown by the previously mentioned examples. For example, in channelopathy-associated insensitivity to pain, a patient loses the ability to sense injuries which results in injuries often going unnoticed before it is too late. As a result, people with this condition often die in childhood through self inflicted injuries such as biting themselves or burns. However, with a modified sequence the loss of function that is experienced could be mild in order to avoid severe symptoms while exploiting pain resistance. Soldiers resistant to pain would be invaluable in combat as they are less affected by debilitating wounds which may induce shock or immobility in others allowing tactical retreats or more effective performance in situations where others would be incapacitated.

Furthermore, other non-physical traits are being investigated such as how genetic modification could potentially be used to reduce the amount of sleep needed by an individual. For example, by studying two families with naturally shorter sleep requirements, a mutation in the GRM1 gene has been discovered [Shi G et al., 2025]^[19].This natural variation in sleep requirements suggests that the gene plays a role in controlling sleep cycles. Additionally, mice studies with genetically modified versions of this allele have found that it causes shorter sleep time without impairing other functions [Shi G et al., 2025]^[20]. In light of this evidence, conclusions can be drawn highlighting that a possible altering of the human version could reduce the amount of time needed for sleep. As previously mentioned, some individuals require less sleep. While the average suggested duration of sleep is 8 hours, some individuals can function with far less due to individual differences [Cleveland Clinic, n.d.]^[21]. This gives merit to the idea of genetically altering the gene in order to reduce sleep requirements as lower dependency on sleep is proven to be biologically possible. Soldiers who require less sleep while functioning perfectly on both a cognitive and physical front would be more efficient in warfare, able to fulfill missions for longer or outlast the opponents in a battle of attrition. However, the impact of long term lack of sleep remains unclear which as a result acts as a potential limitation.

Finally genetic modification can also impact psychological functions. For example, the modification of the NR3C1 gene will be discussed with it being the most ethically dubious so far. This is because modification of the NR3C1 deals with not only physical components but the direct alteration of the mind leading to concerns over concepts such as free will. The NR3C1 gene takes part in the HPA axis (a stress feedback loop) by encoding for glucocorticoid receptors responsible for controlling the release of hormones such as cortisol which return the body to a state of homeostasis after stress [National Center for Biotechnology Information, 2025]^[22]. Through testing with a sample of thirty two patients suffering from PTSD, research has linked the development of PTSD to polymorphisms (different versions) and epigenetic modifications of the NR3C1 gene, which dysregulate this entire stress feedback loop [Ramírez, González Claudia, 2020]^[23]. As a result, a strong correlation can be drawn between the NR3C1 gene and the development of PTSD however, to prove a direct causation further research must be performed. Despite this, it is accurate to say that the NR3C1 gene does have an impact on the development of PTSD in some way. This raises theoretical questions about whether future interventions might one day aim to reduce the risk of developing the disorder. Within warfare, this would be an exceptional benefit as it might increase soldiers' resilience to developing the disorder meaning they may be less emotionally compromised during battle or campaigns along with increasing the chance of an easy re-entry into everyday life.

Current limitations of genetic modification

While the potential benefits of genetic modification are vast, current technology heavily restricts our capabilities. One of the major issues is the delivery of the genetically modified allele. Issues arise surrounding this delivery due to the fact that once an individual is fully grown, billions of specifically targeted cells would need to be edited which is highly unfeasible. Furthermore, current gene editing equipment such as CRISPR, while highly efficient, is not perfect as it may cause off-target effects. Attempting to genetically modify such a quantity of cells would inevitably result in CRISPR causing an off-target effect such as removing one too many base pairs or targeting the wrong type of cell. The results of this could be catastrophic such as encouraging iatrogenic cancerous growth.

However, there is a solution to this issue called germline editing. Germline editing is the process of using genetic modification techniques to alter the genome of an embryo [American Society of Gene + Cell Therapy, n.d.]^[24]. The desirability of germline editing stems from the fact that embryos only contain a few cells meaning less has to be edited reducing the possibility of mistakes. Despite this, Germline editing has one major drawback; ethical concerns. Germline editing is heavily unethical due to the fact that embryos cannot consent to having their fundamental nature altered. Furthermore, germline editing makes the new modification heritable which means it would be passed down to future generations. This systemically changes the human gene pool. As a result, germline editing is banned in most major countries as the future effects of the modification are unpredictable and cannot simply be reversed. For example, a genetic allele may increase the risk of cardiovascular disease by ten percent and then governments are unable to mitigate the effects as the gene has already entered the genetic pool.

The logistics of long term genetic modification in a military setting must also be analysed. On a large scale, genetic modification is probably unlikely due to the high cost and healthcare that must be provided in case of adverse effects. Therefore, full scale genetic modification is unlikely and is more suited to a small group of selected individuals such as a special task force.

Bioweapons

Under international law, biological weapons are banned according to the Biological Weapons Convention (1972) [United Nations Office for Disarmament Affairs, n.d.]^[25] especially for offensive purposes. While offensive research is prohibited, many nations still have defensive programs. However, countries such as Iraq and the USSR have broken the treaty in the past showing compliance has not been universal.

As an overview, genetic engineering in pathogens varies from the standard introduction of antibiotic resistance to the replication of an entire pathogen from scratch. For example, the poliovirus was replicated synthetically de novo [Cello, Jeronimo et al., 2002]^[26] mirroring the potential capabilities of genetic engineering in replicating extinct or heavily restricted natural pathogens. One pathogen of significant concern is smallpox, this is due to its high infectivity and mortality rate coupled with the fact that the population is now unvaccinated against it. This fear is further validated by the fact that researchers have been able to synthesise immunomodulatory proteins of smallpox in order to understand its virulence mechanisms [Ariella, M. Rosengard et al., 2002]^[27]. While the increase in complexity from synthesising an immunomodulatory protein to the whole pathogen is significant, it still highlights the dual-use potential of modern molecular biology.

However, the utilisation of naturally existing pathogens is only one area of concern regarding the applications of genetic engineering principles to bioweapons. Another is of course the genetic modification of the pathogen itself where the balance between virulence, infectivity and a suitable delivery mechanism is far easier to design. For example, there are concerns that genetic modification could make future pathogens harder to treat. Case in point, anthrax is currently treatable with antibiotics [Cennimo, J David et al., 2023]^[28]. However, future technological advances raise concerns that pathogens such as anthrax could become harder to treat if antibacterial resistance were ever engineered into them.

Furthermore, genetic engineering has been used for applications in warfare aside from direct attacks on humans. For example, the US has previously considered and proposed the application of genetically modified pathogens in destroying military stealth paint for ease of identifying enemy fighters. Furthermore, genetically modified pathogens can be designed to target fauna such as the US having considered using GM Fusarium EN-4 in order to destroy drug plants in Colombia [Project Censored, 2010]^[29]. While these pathogens may not directly affect humans, it represents a potential overreach of morals regarding the use of biological weapons where countries are becoming more comfortable with “non-lethal versions”. This may pave the way to further experimentation and ultimately human testing in the future.

Conclusion

To conclude, genetic engineering is likely to have significant impacts on the military as it is likely the benefits may be viewed as outweighing the ethical objections. Even if global governments publicly denounce the technology there is a debate to be held as to whether they are perfecting it in secret such as China who have already altered human embryonic cells to be more resistant to radiation [Chen, Stephen, 2023]^[30] showing the ethical concerns of germline editing are already being challenged. As a result, it is plausible that this technology will become increasingly relevant to military capabilities however, the extent to which its potential is reached is not certain as the technological barriers still exist as a major bottleneck.

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