[snopercod]

Not that we could detect the launch preparations for the liquid-fueled ICBM...

I believe we can. You can see the propellant trucks near the launch pads, and certain venting. I'm not aware that China has self-contained underground silos, but I could be wrong.

[Poohbah]

I believe we can. You can see the propellant trucks near the launch pads, and certain venting. I'm not aware that China has self-contained underground silos, but I could be wrong.

You're wrong. They're self-contained silos, and the fuel is transferred via underground pipes.

Since the DF-5 is basically a Titan II knock-off, it's probably capable of being fueled in less than ten minutes.