I am not impressed by Chinese cruise missiles.
The carrier battle group has a sensor umbrella of 250 miles.
RIM-162 ESSM has the ability to be quad-packed in the Mark 41 VLS. That is 32 ESSMs in a single 8 cell VLS.
There is also the Phalanx CIWS, RAM and electronic jamming.
Yes, the CVBG (and the amphibious expeditionary strike group) have a protective bubble. The CVBG can, with its E-2C/D Hawkeye AWACS, extend the radar horizon between 250 to 350 miles from the carrier. The AESG does not have an airborne equivalent to the E-2C/D, and its defensive bubble depends on the radar range of its escorting CGs and DDGs. The result is the AESG has a sensor range of about 100-150 miles.
The LPD-17 class was to have the Mk 41 VLS that carried four RIM-162 Evolved Sea Sparrow Missiles (ESSM) in the Mk 25 “quad pack”. If the Mk 41 were fitted to the LPD-17 class (and it is NOT), a 16-cell MK 41 VLS loaded with as many Mk 25 “quad packs” could put up 64 individual ESSM. The ESSM has a much longer range than the RIM-116 RAM.
However, there's one problem with ESSM: it is NOT a fire and forget bird like the RAM. The ESSM uses semiautomatic radar guidance and that means its target must stay illuminated by the fire control radar until the missile impacts the target. Once a kill by the ESSM is made, another target can be engaged. ESSM is not designed for a saturation attack. RAM is much better because once it achieves target lock, it will kill that target without further assistance from the ship's fire control.
I would prefer the LPD-17s were equipped with two Mk 15 Mod 0 Block 1B Phalanx CIWS. These 20mm Gatling guns would backup both the MK 49 RAM launchers and the Mk 46 30mm guns. The Navy has decided NOT to do this and it will not be done.
BTW, one of our LPD-17 class recently transited the Suez Canal in daylight. The captain was so nervous about attacks from the shoreline that he mounted eight Mk 16 tripods on the main deck and 01 level of the LPD [bringing the total to ten .50 mg]. The additional .50 machine guns, their cradles, and ammunition trays were borrowed from USMC vehicles embarked on the ship. Sometimes it is better to act to protect your ship than ask permission. The LPD transited the Suez safely and the borrowed armament was returned to the Marines.
Yes, there are countermeasures available to the LPD-17 class. One is AN/SLQ-25A Nixie (an anti-torpedo decoy), another the is AN/SLQ-32A(V)2 ESM and ECCM suite, there's the pair of Mk 36 SRBOC mortars (2x12 or 24 tubes), and finally the Mk 53 Nulka (an ASM decoy) mounted on the SRBOC mortars (total of 8 decoys). However, this all supposes the ship's combat system is working at 100 percent efficiency.
I'd be more interested if the Navy would invest more in stand alone defensive systems that don't need to depend on the ship's combat system. These are the Mk 49 ROSAM (a remotely operated .50 mg — USN version of the Israeli Mini-Typhoon), CIWS/Phalanx, and SeaRAM (with an 11-round RAM launcher that replaces the CIWS 20mm Gatling).