Government uniforms aren't made of magical cloth that exempt the wearer from basic morality.

The government, being an organizational monopoly on the initiation of force in society, is seemingly magical in the minds of mankind. It can by fiat invert basic human morality as a fundamental tenet of it's very existence.

While the individual cannot take what he wants without permission, the government levies taxes, fees, fines, and confiscation on it's human cattle to fund it's mission of hierarchical authority.

While no individual can aggressively kill or maim others without moral outrage and ostracism being exacted upon them, they can simply join the government, put on a drab costume, and commence mass murder of their fellow man as long as such murder aligns itself with the will of their government.