So, I like to take a step back and take a wider looks at things sometimes, so I've been thinking about how the recent developments of the PLA can be used in an integrated warfare situation. Looking at the geopolitical side, it seems like China has focused on stabilizing its borders to the west, while leaving more room for maneuvers to the east. This in effect reduces the need of a strong army, allowing the PLA to focus more of their resources on the Navy and the Air Force. Another consequence of this strategy is that any conflict involving China in the foreseeable future will likely involve major naval engagements(Korea, Taiwan, Diaoyu, Vietnam, even India to a lesser extent), likely with direct or indirect participation of the U.S. navy. Thus, one of the most pressing issues facing the PLA would be how to effectively neutralize by far the most powerful navy on earth.
Now, looking at the history of the PLA, it seems that they've been generally pretty practical and realize their limitations. Since it's unlikely that the Chinese navy and air force can catch up to American levels in the near future, they must be looking for more innovative, more asymmetric methods of fighting them should the need occur. Looking at the J-20 and the DF-21D, it seems to me that the best way for realizing that goal would be an all-out sensor-denial campaign.
The J-20, though a very advanced platform, will likely still encounter great difficulty penetrating American CVG's, and there are some serious doubts over whether it can even carry AShM's. The DF-21D, though a menacing weapon, will likely still have trouble scoring direct hits on American capital ships. However, a BVR missile equipped J-20 should have a good shot of slipping through the periphery of the defense and establish essential no go zones against American AWACS, while staying mostly out of range of ship-borne weapons and holding their own against American fighter jets. The DF-21D, on the other hand, could use airburst weapons raining thousands of pellets onto American ships(not just CV's). This won't sink them or even damage the flight deck much, but it may very well knock out most of the exposed sensors and communication links. This eliminates the need to score direct hits on carriers and thus drastically decrease the necessity of precise and accurate terminal guidance.
The result would be a severe disruption in the highly touted and prized integrated fighting network of the USN, dramatically limiting their freedom of operation as they will be restricted to operating close to friendly shores under the umbrella of protective land-based platforms. IMO, with the advancement of long-range precision weaponry, the future of warfare will be based on sensors and sensor-denial, and the J-20 and the DF-21D can serve as great platforms in such a war.
