And this is just one of the many many ideas. You would also need near perfect infosec to make sure your orbital weaponry doesn't get stolen away from you and you are the biggest, shiniest target imaginable.
An ICBM with what payload exactly? With a nuke? Getting your hands on a nuke is hard. But, if by some miracle, you managed to launch one into space, then no later than you'd start threatening regulators with it, your nuke would eat a satellite interceptor.
> Just wait until someone surreptitiously puts up a whole network of sleeper nukes into orbit. One weird trick to become world emperor, eh?
Near-impossible to pull off at this point, as it would require absurd world-wide levels of incompetency in tracking nuclear material and space launches. That, or new technology for doing damage (this was a side plot in an excellent hard sci-fi book, A Sword Into Darkness, where a fictional propulsion system created by a private company could also work as a sort-of fusion bomb, without radioactive material).
Things might get easier if humanity expands meaningfully beyond GEO.
Also, even if you put a single "rod of God" in orbit, the moment you've threatened anybody with it, an attempt to shoot it down will be made. If you manage to drop it on someone, it'll only add extra mass murder charges onto your life sentence or execution.
Just wait until someone surreptitiously puts up a whole network of sleeper nukes into orbit. One weird trick to become world emperor, eh?
A good sci-fi plot, since it's likely do-able by private firms in the near to medium term.
That said there are more mundane ways to escape. However those come with their own risks (ask Gerald Bull how his attempt turned out).