Obviously it takes an individual to carry out the violence, but governments have been responsible for organizing mass violence. The millions of deaths from war

Obviously it takes an individual to carry out the violence, but governments have been responsible for organizing mass violence. The millions of deaths from war would have been extremely unlikely to happen unless orchestrated by a government. The exception would be the mexican drug war, but even that could be argued to be caused by government enforced prohibition. Even so, the deaths caused by the cartels are low compared to deaths from wars and genocides that governments have carried out.