Probably mostly because they are depraved sickos who get off on death, suffering, and ratings. This is a grotesque sport to them.

Secondly because Hassan committed the attacks as a soldier on a US base. Hegseth probably wants to send a message to other soldiers of the consequences of such actions. He’s been doing that since day one in the role.

Thirdly Hassan is a Muslim and grew weary of the horrors inflicted upon predominately Muslim nations by the US military. Can’t have anyone starting to have ethics in the military. Islamophobia runs deep in the US government.

But let’s be real at the end of the day every justification for this will backfire. Potential copycats will watch and see themselves as a future star of the same series. The show of force to deter copycats will only do the opposite. That’s basically been the lesson of every US military engagement since the Korean War but even further to the merciless genocide campaigns against the indigenous folks of North America.