My personal opinion, "One World Government" has been in the works for a very long time, it is just a matter of "when" now until it becomes officially.
For example, a what if scenario, you have some kind of One World Government that appears to pop up out of nowhere in the wake of some kind of emergency, that as a consequence of major war of some kind, just enough to result in the entire monetary system collapsing, you have people in the streets looting and rioting, food scarcity and other needs for survival, and as a result, there needs to be martial law of some kind to get society back on track.
So what if during some kind of war out break, because of diseases and stuff, people need to get immunized, so what if some kind of Mandated Vaccination Program to be enforced? Nanotechnology, Recombinant DNA, RFID/NFC chip implants of some kind all this stuff can easily be done via a Vaccination of some kind in my opinion.
So what happens then to those who refuse to go along with the flow? The outcasts? The rebels? The troublemakers? (as this is how such people will be seen). So for people such as these, disposal or execution is a method that can be used to deal with such rogue elements in society, and with food scarcity, what about all the dead bodies of those who were disposed of because they didn't join the system?