Why China MIRVs Some Of Its ICBMs?

[Broccoli]

Jeffrey Lewis offers good answer for that.

Podcast can be listened in here.
http://armscontrolwonk.com/archive/5456/china-mirvs-some-missiles

China would surely prefer to retire the older DF-5 warhead design in favor of a more modern design. And using the newer, smaller warhead leaves tons of room. Literally tons. The DF-5 has between 3,000 and 3,200 kilograms of “throw weight” (that’s how much stuff it can heave across the globe). Even if about half the payload goes to the post-boost vehicle, there’s enough oomph left over for three or four 500 kg warheads. What else would one do with all that space? Add some penetration aids (decoys and so forth) to defeat missile defenses? Sure, but that’s a couple hundred kilograms max. Fill it with ballast for stability? Or maybe those little balls from Panda Pop?

http://foreignpolicy.com/2015/05/26...uclear-warhead-missiles-arms-race-deterrence/