The civil servants work on what Congress and the President set as priorities. They cannot execute plans that span multiple Congresses and Presidential administrations unless every single Congress and Administration over that time period agrees to support the plan.
They built a horrifying arsenal.
I really do not see why they cannot build a health system. They have done so here.
Yes, because three successive Presidential administrations and six successive Congresses supported it.
More precisely, two successive administrations and about four successive Congresses supported it. The third administration began to back off, as did the fifth Congress; then the sixth Congress, along with the administration, stopped supporting it--and the moon missions stopped. Despite the fact that a large number of civil servants were making cogent arguments for why they should continue.
> They built a horrifying arsenal.
Yes, because every President and every Congress since 1945 has supported it.