Which Major Command (MAJCOM) is responsible for aspects of the US nuclear triad?

The Air Force Global Strike Command is indeed the Major Command responsible for the aspects of the US nuclear triad. This command is specifically tasked with maintaining the United States' nuclear deterrent capabilities, which encompass land-based intercontinental ballistic missiles (ICBMs), strategic bombers, and submarine-launched ballistic missiles (SLBMs).

The Global Strike Command oversees the operations, training, and maintenance necessary to ensure these nuclear forces are ready to carry out their strategic deterrent mission. This includes not just the deployment of these weapons, but also ensuring that all related operations adhere to safety, security, and other critical protocols associated with nuclear capabilities.

In contrast, while the other Major Commands have their own important roles within the Air Force, they do not have direct responsibility for nuclear operations. For example, Air Force Space Command manages space operations, Air Mobility Command handles air mobility and logistics, and Air Combat Command focuses on fighter and bomber operations but does not oversee the entirety of the nuclear triad operations. Thus, Air Force Global Strike Command's specific focus on nuclear deterrence and strategic capabilities establishes it as the correct answer in relation to the question about nuclear triad responsibilities.