An excerpt from a Congressional Research Service report on countering the DF-21D.
Breaking the ASBM’s Kill Chain
Countering China’s projected ASBMs could involve employing a combination of active (i.e., “hard-kill”) measures, such as shooting down ASBMs with interceptor missiles, and passive (i.e., “soft-kill”) measures, such as those for masking the exact location of Navy ships or confusing ASBM reentry vehicles.
Employing a combination of active and passive measures would attack various points in the ASBM “kill chain”—the sequence of events that needs to be completed to carry out a successful ASBM attack. This sequence includes detection, identification, and localization of the target ship, transmission of that data to the ASBM launcher, firing the ASBM, and having the ASBM reentry vehicle find the target ship.
Attacking various points in an opponent’s kill chain is an established method for countering an opponent’s military capability. A September 30, 2011, press report, for example, quotes Lieutenant General Herbert Carlisle, the Air Force’s deputy chief of staff for operations, plans, and requirements, as stating in regard to Air Force planning that “We’ve taken [China’s] kill chains apart to the ‘nth’ degree.”
In an interview published on January 14, 2013, Admiral Jonathan Greenert, the Chief of Naval Operations, stated:
"In order for one to conduct any kind of attack, whether it is a ballistic missile or cruise missile, you have got to find somebody. Then, you have got to make sure it is somebody you want to shoot. Then, you’ve got to track it, you’ve got to hold that track. Then, you deliver the missile. We often talk about what I would call hard kill—knocking it down, a bullet on a bullet—or soft kill; there is jamming, spoofing, confusing; and we look at that whole spectrum of operations."
"And frankly, it is cheaper in the left-hand side of that spectrum."
To attack the ASBM kill chain, Navy surface ships, for example, could operate in ways (such as controlling electromagnetic emissions or using deception emitters) that make it more difficult for China to detect, identify, and track those ships.
The Navy could acquire weapons and systems for disabling or jamming China’s long-range maritime surveillance and targeting systems, for attacking ASBM launchers, for destroying ASBMs in various stages of flight, and for decoying and confusing ASBMs as they approach their intended targets. Options for destroying ASBMs in flight include developing and procuring improved versions of the SM-3 BMD interceptor missile (including the planned Block IIA version of the SM-3), accelerating the acquisition of the Sea-Based Terminal (SBT) interceptor (the planned successor to the SM-2 Block IV terminal-phase BMD interceptor),
and accelerating development and deployment of the electromagnetic rail gun (EMRG), and solid state lasers (SSLs). Options for decoying and confusing ASBMs as they approach their intended targets include equipping ships with systems, such as electronic warfare systems or systems for generating radar-opaque smoke clouds or radar-opaque carbon-fiber clouds, that could confuse an ASBM’s terminal-guidance radar.
An August 9, 2014, press report states that Admiral Harry B. Harris, Jr., Commander, U.S. Pacific Fleet, in response to a question about the threat posed to U.S. Navy aircraft carriers by China’s ASBMs, stated, “We are very well aware of the capabilities that China has and is trying to develop and I’m very confident we would be able to carry out any mission that we have to.” The press report states that Harris said he could not state the nature of the technology used to counter the ASBM, but that “We work in it every day. I’m confident of our ability to defeat any Chinese missile threat and to be able to do whatever we need to do.”
A May 29, 2014, press report states:
When the next-generation aircraft carrier CVN 78 Gerald R. Ford takes to the seas later this decade, it will face one of the most dangerous threats to the U.S. maritime military behemoth—the Chinese DF-21 anti-ship ballistic missile (ASBM).
But U.S. Navy officials remain confident that the technological improvements to the Ford as well as the other ships shielding the carrier from attack should be able to protect the vessel....
... zeroing in on a carrier with such a missile is more difficult than it seems, says Rear Adm. Michael Manazir, director of air warfare.
Eyeing the Ford from the ship’s flight deck, he notes: “People think this is a big target. But they have to get to the carrier and then discern that it is a carrier.”
In addition, the U.S. Navy has a layered network of defensive systems.
“It’s a series of systems,” Manazir explains during a recent exclusive tour of the Ford at the Newport News Shipbuilding yard in the Tidewater part of Virginia. “We want to attack it on the left side of the kill chain.”
A May 21, 2014, press report states:
When asked whether a new Chinese anti-ship weapon—the DF-21D missile—might render carriers obsolete in the Pacific, [Admiral Jonathan] Greenert [the Chief of Naval Operations] said the U.S. is developing countermeasures to protect the prized vessels from the weapon that is sometimes referred to as a “carrier killer.”
“It’s a good weapon that they’ve developed. But there’s nothing that doesn’t have vulnerabilities, and we continue to pursue ideas in that regard. … We’re working quite feverishly on that, and I’m pretty comfortable with where we can operate our carriers,” Greenert said.
The Navy chief said the U.S. has “lots of intelligence” on the Chinese weapon, but wouldn’t elaborate, nor would he discuss what specific steps the military is taking to counter it.
In the future, Greenert said that new electromagnetic weapons, unmanned aircraft and other standoff weapons will help mitigate the threat of anti-ship missiles.
An April 24, 2014, press report states that:
The U.S. Navy has no silver-bullet concept to defeat the Chinese DF-21 anti-ship ballistic missile (ASBM), but will rather rely on a network of defensive systems to do the job.
“It’s a series of systems,” Rear Adm. Michael Manazir, director of air warfare, tells the Aviation Week Intelligence Network (AWIN). “We want to attack it on the left side of the kill chain.”
During an exclusive tour and interview this month of the next-generation aircraft carrier CVN-78 Gerald R. Ford while under construction at the Newport News Shipbuilding yard in Virginia, Manazir says, “People think this is a big target. But they have to get to the carrier and then discern that it is a carrier.”
The Navy’s various networks of defensive shields aboard the carrier, and other vessels elsewhere, will make that very difficult, he says.”
Document: Report to Congress on Chinese Naval Modernization and Implications for U.S. Navy - USNI News