I don't understand. The article from your link(globalsecurity) is the same as the one I posted( from fas.org). So what exactly is our difference?
A direct quote from your link:
"With an estimated range of only 8,000 km (4,300 nm), the DF-31 can only reach targets along the entire West Coast of the United States and in several northern Rocky Mountain states. Chinese incentives for deploying a missile with such limited capabilities are not self evident.
The DF-41, a 3-stage 12,000 km-range missile similar to the American Minuteman and the Russian Topol SS-25, will apparently be developed using the first two stages of the DF-31 along with a much larger third stage. The larger third stage and longer range of the DF-41 is made possible by the fact that, unlike the DF-31, the size of the DF-41 is not constrained by the requirement that it be fitted into a submarine launch tube. The cancelled 1,700km-range DF-25 ground mobile missile was developed using the first two stages of the DF-31.
In August 2001 it was reported that China was developing a longer range version of its DF-31, designated the DF-31A. The DF-31A will reportedly be able to cover targets throughout the continental U.S. from mainland China."