3.1 Overall forecast of combat process and attrition
According to the simulation results, the entire battle lasted 2 h 35 min, and the red force achieved its expected goal. The total attrition and the rate of attrition are shown in Fig. 8. At the beginning of the battle, the artillery and air strike forces of both sides were focused on the force build-up area of the opposing side, which led to a large number of casualties in the early stages. The first peak in attrition occurred when the red force broke through the first line of defense of the blue side, forcing the ground forces of the two teams to engage. The second peak of attrition occurred during the red force’s advance from the front line to the reserve position. The third wave of attrition occurred when the red force broke through the blue force’s reserve position. At 65 minutes after the battle began, the blue polyline, indicating the attrition rate, exceeded the red polyline when the reserve of the red force joined the battle, causing the blue side’s defensive forces to be largely eliminated, and the attrition rate of the blue force exceeded that of the red force.
The red force’s total combat attrition was 15.91%. The level of attrition for specific combat groups was 23.15% for the first batch of the main attack group, 23.9% for the assist attack group, 24.91% for the second batch, 22.62% for the information warfare group, 6.43% for the artillery group, and 1.11% for the support protection group. In addition, the red force lost 13 pilots. The total combat attrition of the blue force was 42.9%. For the red force, 70.5% of the total attrition belonged to its three ground assault groups. Although the information warfare group was behind the battlefield and did not directly face the enemy, its combat attrition accounted for 15.1% of the total. In the total attrition of the red force, 30% of the attrition was caused by directly-aimed weapons, 16% was caused by indirectly-aimed artillery, and 54% was caused by air strikes
3.2 Casualty forecast
We have analyzed the personnel injuries of the simulated battle according to injury severity, cause of injury, injury type, and injury site, and at the same time compared the simulated injury situation to portions of the personnel injury data from the Vietnam War【27】 (March 1966–July 1967), the Gulf War 【28】(August 1990–February 1991), the Serbian Offensive in Eastern Slavonia【29】 (September 1991–July 1992), the First Chechen War(December 1994–August 1996), the Second Chechen War【30】(August 1999–May 2000), and the Operation Iraqi Freedom【31】 (September 2004–September 2005). Through chi-square analysis, we summarized the characteristics of modern combat warfare【32】. The injury data of the above 6 wars were all from publicly available literature. Due to limited data, it cannot be guaranteed that the numbers of injured personnel were the same when the simulated data were compared to those of the 3 previous wars according to injury severity, cause of injury, injury type, and injury site. Moreover, the number of casualties in the statistics also differed from the total number of injured personnel in the previous wars.
3.2.1 Injury prediction
For the red force, the number of troops killed in the battle amounted to 27.1% of the total attrition. Among the casualties, 23.7% of the total number of injured individuals were critically injured or severely injured, 37% were moderately injured, and 39.2% had minor injuries. The injury distribution situation of the simulation was compared to the combat data from the Gulf War, the First Chechen War, and the Second Chechen War (Table 1). The overall trend exhibited a drop in the percentage of minor injuries and an increase in the percentage of severe injuries.
Table 1
Comparison of injuries between simulation results and actual combat data
Injury level | Simulation system | Gulf War | First Chechen War | Second Chechen War |
Number | %Percentage | Number | %Percentage | Significance | Number | %Percentage | Significance | Number | %Percentage | Significance |
Minor injuries | 180 | 39.2 | 73 | 67.6 | Yes,< 0.01 | 3975 | 49.4 | Yes,< 0.01 | 797 | 40.5 | No,0.61 |
Moderate injuries | 170 | 37.0 | 17 | 15.7 | Yes,< 0.01 | 2407 | 29.9 | Yes,< 0.01 | 655 | 33.3 | No,0.13 |
Severe and critical injuries | 109 | 23.7 | 18 | 16.7 | No,0.11 | 1665 | 20.7 | No,0.12 | 515 | 26.2 | No,0.28 |
The distribution of injuries in each combat group is shown in Fig. 9. One notable feature is that the fraction of minor injuries decreased while the fraction of severe injuries and critical injuries increased. In particular, more than 50% of the casualties were in the artillery group and the logistical group. In addition, once an aircraft performing air strike missions was hit, more than 50% of the aircrew died. Most of the parachuted aircrew were severely or critically injured, posing new challenges for search and rescue missions.
3.2.2 Prediction of injury causes
Through simulation, we obtained the distribution of the cause of injury for this operation and compared it with relevant data from the Vietnam War, the First Chechen War, and the Second Chechen War (Table 2). The simulation predicted that 25.1% of the injury-caused attrition of the red force was due to blast injuries, while impact wounds and burn wounds accounted for 35.5% and 10.2% respectively, both of which were higher than those seen in previous combat statistics, and all 3 combining for a total of 70.8%. In this situation, the number of injuries due to gunshot wounds and blade injuries that occurred frequently in traditional battles has decreased, indicating that the role of light weapons is less than in the past. In addition, the number of combined injuries, including fragment impact, and burn-blast injury has increased and accounted for 25.1% of the total. The increase in the number of individuals suffering combined injuries poses a severe challenge to the rescue of wounded.
Table 2
Comparison of injury causes between simulation results and actual combat data
Cause of injury | Simulation system | Vietnam War | First Chechen War | Operation Iraqi Freedom |
Number | %Percentage | Number | %Percentage | Significance | Number | %Percentage | Significance | Number | %Percentage | Significance |
Gunshot wounds and blade injuries | 19 | 4.1 | 4565 | 32.0 | Yes,< 0.01 | 4266 | 26.5 | Yes,< 0.01 | 202 | 24.1 | Yes,< 0.01 |
Blast injuries | 115 | 25.1 | 8485 | 59.4 | Yes,< 0.01 | 9482 | 58.9 | Yes,< 0.01 | 489 | 58.4 | Yes,< 0.01 |
Burn wounds | 47 | 10.2 | 200 | 1.4 | Yes,< 0.01 | 885 | 5.5 | Yes,< 0.01 | 25 | 3.0 | Yes,< 0.01 |
Impact wounds | 163 | 35.5 | 534 | 3.7 | Yes,< 0.01 | 1078 | 6.7 | Yes,< 0.01 | 96 | 11.5 | Yes,< 0.01 |
Combined injuries | 115 | 25.1 | 500 | 3.5 | Yes,< 0.01 | 386 | 2.4 | Yes,< 0.01 | 26 | 3.1 | Yes,< 0.01 |
In the distribution of the specific cause of injury in each of the combat groups of the red force, all the gunshot wounds and blade injuries occurred in the ground assault cluster, but the overall frequency of occurrence of gunshot wounds and blade injuries was generally low indicating that, in actual combat, due to the long range and high accuracy of new directly-aimed weapons, light weapons have only a limited role. Therefore, the main threat faced by troops performing ground combat tasks is still from the enemy’s long-range directly-aimed weapons such as artillery and anti-tank missiles. The artillery group and the logistical group do not participate in frontal offensive operations, but they are key targets for the enemy’s long-range firepower and air strikes, so the injuries suffered by these two groups were mostly impact wounds, burns, and combined injuries caused by explosions.
3.2.3 Prediction of injury types
For the distribution of injury types in the red force, 30.7% of the total were penetration wounds, 19.0% were fractures, dislocations, or broken limbs, and 18.5% were contusions and soft tissue injuries. These were the top 3 injury types. According to our analysis, this was due to the high proportion of artillery and air strikes in modern warfare, in which explosion fragments cause a large number of penetrating wounds. Further, explosions in confined environments such as vehicle cabins can easily cause internal organ contusion and limb fractures. In addition, due to the reduced number of bullet wound injuries, penetrating wounds, and cut wounds caused by bullets, accounted for only 7% and 3% of all injury types respectively, which is significantly lower than in historical data (Table 3).
Table 3
Comparison of injury types between simulation results and actual combat data
Injury type | Simulation system | Vietnam War | Serbian Offensive in Eastern Slavonia | Operation Iraqi Freedom |
Number | %Percentage | Number | %Percentage | Significance | Number | %Percentage | Significance | Number | %Percentage | Significance |
Fractures, dislocations, or broken limbs | 87 | 19.0 | 7537 | 14.9 | No,0.02 | 330 | 27.3 | Yes,< 0.01 | 154 | 15.6 | No,0.12 |
Contusions and soft tissue injuries | 85 | 18.5 | 2495 | 4.9 | Yes,< 0.01 | 205 | 16.9 | No,0.44 | 62 | 6.3 | Yes,< 0.01 |
Penetration wounds | 141 | 30.7 | 14137 | 28.0 | No,0.19 | 217 | 17.9 | Yes,< 0.01 | 223 | 22.6 | Yes,< 0.01 |
Blind tracks, cuts, and penetration wounds | 48 | 10.5 | 24169 | 47.8 | Yes,< 0.01 | 318 | 26.3 | Yes,< 0.01 | 489 | 49.6 | Yes,< 0.01 |
Blood vessels, nerves, and other injuries | 98 | 21.4 | 2235 | 4.4 | Yes,< 0.01 | 141 | 11.6 | Yes,< 0.01 | 57 | 5.8 | Yes,< 0.01 |
In terms of the specific injury type distribution of the combat groups in the red force, the ground assault cluster not only faced the assault of directly-aimed weapons by the ground defense of the blue force, but also the attack of indirectly-aimed weapons and air strikes of the blue force. As a result, this cluster suffered penetrating wounds, contusions, fractures caused by explosions, and other types of injuries to the skin and soft tissue due to burns, as well as penetrating injuries, blind track injuries, and tangential injuries that are mainly caused by bullets from light weapons. This complexity of types of injury poses a challenge for the rescue of the wounded on the battlefield. Although the artillery group and the logistical group are concentrated behind the battlefield, they still face the threat of long-range enemy fire. Their injury types are mainly penetrating wounds, contusions, skin and soft tissue injuries, and fractures.
3.2.4 Prediction of injury sites
Among the injured of the red force, head, face, and neck injuries accounted for 18.7% of the total number of wounded, and the proportion of upper limb injuries was 17.9%. These statistics are relatively close to the relevant previous data. Chest and back injuries accounted for 24.6% of the total number of wounded, while abdominal (waist) injuries accounted for 15.9%, higher than that in the historical data. Analysis showed that this was mainly because most of the weapons used in combat were vehicle-borne, and most of the combat personnel were in the cabins of armored vehicles. As the trunk of the body has a greater surface area than that of the limbs, this makes chest and back injuries more likely in this situation. The proportion of lower limb injuries was 22.9%, lower than that in the historical data. Analysis revealed that, given the fact that modern troops are basically vehicle-mounted, the chances of infantry leaving the vehicle to fight is reduced, thus resulting in a decrease in the proportion of lower limb injuries (Table 4).
Table 4
Comparison of injury sites between simulation results and actual combat data
Injury site | Simulation system | Vietnam War | First Chechen War | Operation Iraqi Freedom |
Number | %Percentage | Number | %Percentage | Significance | Number | %Percentage | Significance | Number | %Percentage | Significance |
Head, face, and neck | 86 | 18.7 | 4180 | 15.7 | No,0.07 | 5715 | 35.5 | Yes,< 0.01 | 203 | 21.7 | No,0.2 |
Chest and back | 113 | 24.6 | 3490 | 13.1 | Yes,< 0.01 | 1384 | 8.6 | Yes,< 0.01 | 127 | 13.6 | Yes,< 0.01 |
Abdomen, waist, pelvis, and perineum | 73 | 15.9 | 3048 | 11.4 | Yes,< 0.01 | 1288 | 8.0 | Yes,< 0.01 | 141 | 15.1 | No,0.69 |
Upper limbs | 82 | 17.9 | 7106 | 26.7 | Yes,< 0.01 | 3155 | 19.6 | No,0.36 | 157 | 16.8 | No,0.62 |
Lower limbs | 105 | 22.9 | 8838 | 33.1 | Yes,< 0.01 | 4555 | 28.3 | Yes,0.01 | 307 | 32.8 | Yes,< 0.01 |
Of all the combat injury attritions in the red force, 302 individuals had single wounds, 157 were wounded at 2 body sites, and 45 were wounded at 3 or more sites. The percentage of multiple injuries was 34.2%, much higher than the 9.5% in the Russo-Georgian War and the 18% in the Gulf War. Figure 10 shows the distribution in the number of injury sites for the various combat groups of the red force. The percentage of multiple injuries is 29% for ground assault clusters, 31.3% for artillery groups, and 57.5% for logistical groups. As the ground assault sections of the red force are equipped with armored vehicles and the level of personnel protection is high, the number of multiple injuries is low. Although the artillery group and the logistical group are behind the frontline, they lack armor protection and their personal protective equipment is also weak, so their risk of multiple injuries is high.