The real problem with the international government is the fact that people half a world away cannot be relied on to participate as a member of your local society.
There are events in which the community must act together, otherwise it (and the people therein) may perish. People band together to accomplish what the individual cannot. The left is working to use this fact for their benefit, to the huge detriment of everyone else (witness the out-of-state characters rioting in Charlotte).
That's one problem. The rulers and the rules are out of touch.
I believe there's another: The chain of command can only get so long, with so many levels, before it becomes ineffective or breaks. The Chinese recognized this millenia ago with their saying, "The mountains are high and the emperor is far away." In management theory, it's known that a given manager can only intensively manage a handful of people. I think a common number given for effective span of direct command is seven. More than that (obviously depending on the situation), and you need an intermediate level of management.
There's also the problem of delay in command execution, or in recognition of a situation that needs addressing working its way up the ladder. In systems with feedback, delay is death--it winds up with instability.
These imperfections in a multi-leveled chain of command can be controlled to an extent with harsh penalties. You see that in Islam. But, there's a limit to how well it works, and certainly to how harmoniously it can work.