The risk was never that large numbers of service members were going to die. The risk was that large numbers of personnel would get sick at the same time, rendering combat units ineffective and overwhelming the capabilities of the military healthcare system. THAT constitutes an actual threat to national security. The military doesn't make members get vaccines, go through physicals, get ailments treated, PT test, etc. because they're concerned about your personal health. They do those things because, at the end of the day, they need people to be combat effective. Doesn't take a whole lot of mental gymnastics to understand the military response to COVID.