Center for Strategic & International Studies (CSIS) Taiwan Wargames

[GR66]

In January CSIS presented their report on a series of 24 wargames they conducted to examine the results of a Chinese invasion of Taiwan.

From the summary of the report:

CSIS developed a wargame for a Chinese amphibious invasion of Taiwan and ran it 24 times. In most scenarios, the United States/Taiwan/Japan defeated a conventional amphibious invasion by China and maintained an autonomous Taiwan. However, this defense came at high cost. The United States and its allies lost dozens of ships, hundreds of aircraft, and tens of thousands of servicemembers. Taiwan saw its economy devastated. Further, the high losses damaged the U.S. global position for many years. China also lost heavily, and failure to occupy Taiwan might destabilize Chinese Communist Party rule. Victory is therefore not enough. The United States needs to strengthen deterrence immediately.

I've put the link to the report in this separate thread but there are lots of take-aways in the report that could either spawn their own threads or inform discussion in other existing threads.

A couple of items that jumped out at me from my brief initial skim of the report were:

Recognize the limitations of Marine Littoral Regiments and Army Multi-Domain Task Forces and cap their numbers.
The Marine Corps is building Marine Littoral Regiments (MLRs) to operate inside the Chinese defensive zone (which the Marine Corps calls the “weapons engagement zone”) and contest Chinese air and naval assets. The Army envisions its Multi-Domain Task Forces (MDTFs) as having a similar function. Although these units could contribute to the fight, neither played heavily in most scenarios. The problems of operating inside the Chinese defensive zone were insurmountable.

[and specifically in relation to their land-based missile launchers}

Ground units will not provide a significant volume of fire. A squadron of bombers armed with longrange cruise missiles has a greater volume of fire than an entire MLR but without the challenges of transportation and logistics. Ground-based anti-ship units must either deploy with a large number of missiles before the conflict begins or act as forward sensors for long-range air and naval power.

Avoid crisis deployments that create vulnerabilities.
U.S. warfighting doctrine includes a pre-hostility phase designed to strengthen deterrence and enhance U.S. warfighting capabilities should conflict occur. As a result, the United States routinely makes forward deployments in crises.303 Therefore, in a major confrontation with China, the United States might load up Japan and Guam with aircraft and move CSGs into the region to signal U.S. resolve. Unfortunately, as Thomas Schelling, the great strategist, observed, “A fine deterrent can make a superb target.”304 In early 1941, the United States transferred the home base of the Pacific Fleet from San Diego to Pearl Harbor, Hawaii, to deter Japanese aggression and station the fleet closer to the potential fight. However, this move put the fleet within range of Japanese striking forces, with results as tragic as they are well known. Similarly, U.S. deployments during a confrontation with China might tempt China to attack preemptively.

Shift to smaller, more survivable ships.
As with aircraft, the United States lost many surface ships in almost every iteration because of forward deployment within the Chinese defensive zone. U.S. losses of large surface ships typically totaled two carriers and 15 to 25 cruisers/destroyers. Although this represented only about 15 to 25 percent of total U.S. Navy surface combatants, losses typically included nearly all large surface ships in the Western Pacific. In the most intense iterations, the U.S. Navy was losing a major ship every day of the war The wargame tracked major surface combatants—carriers, cruisers, destroyers—and attack submarines. It did not track other classes of ships, which collectively comprise over half the fleet and would also have taken losses in a U.S.-China conflict. Until the Chinese ground-launched missile inventory was exhausted, it was too dangerous for U.S. or Japanese surface ships to approach Taiwan. Amphibious ships were particularly vulnerable because of their lack of defensive systems.
...
Even after Chinese ASBMs (Anti-Ship Ballistic Missiles) had been expended, the utility of U.S. surface ships had limits. Although the range of the Maritime Strike Tomahawk (MST) allowed U.S. surface ships to attack Chinese ships from a distance, every MST in a ship’s inventory meant one fewer interceptor or anti-submarine missile that the ship had for defense. A ship with enough MSTs to destroy multiple Chinese warships was a glass cannon, very vulnerable in turn to Chinese attack. Just as there will be too many incoming missiles for active defense to adequately protect airfields, there will be too many anti-ship missiles for active defense to adequately protect surface ships. Therefore, active defense with interceptors must be paired with soft kill measures (e.g., reduced radar crosssection and electronic warfare) that complicate enemy targeting. To this end, the budget of the Surface Warfare Division of the Operational Test and Evaluation Force, which tests ship defenses, should be increased.307 Even with improved electronic warfare, many ships will be lost in a conflict with China because electronic warfare advantages are transitory. Procurement decisions must therefore consider the vulnerability of surface ships. This all points to benefits in shifting toward a fleet of smaller, stealthier ships integrated with unmanned decoys. Such ships would be better disposed to the soft kill of incoming missiles. In addition, it will not be as devastating to lose smaller, cheaper, less-capable ships. The Navy should also have expendable or unmanned ships accompany CSGs to act as decoys.

Develop rescue mechanisms to deal with crippled ships and multiple sinkings.
Just because a ship is sunk does not mean that its problems are over. Hundreds or even thousands of U.S. sailors would be thrown into the water each time a ship sinks. Currently, the U.S. Navy has no way of rescuing these sailors except by diverting a warship, with all the associated risks and opportunity costs.
...
Game participants with a naval background recalled the experience of the USS Juneau in World War II. The ship was torpedoed and sunk on November 13, 1942, leaving 100 sailors in the water. However, the local commander judged it too risky to stop and look for survivors. Only 10 survivors were left when finally picked up eight days later. World War II convoys routinely included a rescue ship to pick up survivors so that warships did not have to be diverted. In addition to their humanitarian function, rescuing 4,200 shipwrecked crew during the war, rescue ships boosted morale by reassuring sailors about their chances of survival.309 Further, many mission kills would not result in the ship being sunk but rather incapacitated. Without appropriate assets to tow disabled ships to port, they would have to be scuttled, depriving the Navy of an irreplaceable asset. For example, in World War II, all five U.S. fleet carriers lost in action were scuttled to keep them from falling into enemy hands after receiving severe damage. The U.S. Navy needs to develop rescue ships that can accompany CSGs and SAGs. Such ships could both rescue shipwrecked sailors and tow disabled ships. Some version of the existing oceangoing tugs (Navy classification: “ATS”) might be suitable. Although this is a lower-priority requirement in peacetime, the wartime need is clear. The nation would be unforgiving if the Navy left sailors to drown because it was too risky to save them. Unlike in 1943, ubiquitous social media would prevent suppression of information about the event. Further, the tugs might save some damaged ships that would otherwise be lost. The Navy will need every ship it has because of the long time required for new construction.


The Navy might also consider acquiring an amphibious patrol aircraft that could help rescue sailors from sunken ships and aircrew from downed aircraft. In a situation where the United States and Japan lose dozens of aircrew a week, each of whom requires millions of dollars and many years to train, such rescues make military sense aside from the humanitarian imperative. The picture shows the Japanese Shin-Maywa US-2, an amphibious aircraft designed for maritime rescue missions.

Prioritize submarines and other undersea platforms.
In every iteration, the U.S. player moved submarines into the Taiwan Strait, where they could attack Chinese amphibious ships directly. Indeed, in the base case, one U.S. submarine squadron begins in the strait because that likely constitutes current deployment practice. Inside the straits, U.S. submarines wreaked havoc on Chinese shipping. Based on the agent-based modeling found in RAND’s U.S.-China Military Scorecard and historical evidence from World War II, each submarine would sink two large amphibious vessels (and an equal number of decoys and escorts) over the course of a 3.5-day turn. Every submarine squadron (four submarines) in the strait sank eight Chinese amphibious ships and eight escorts or decoys, but at a price of roughly 20 percent attrition per 3.5 days. U.S. submarines operated on a “conveyor belt,” whereby they hunted, moved back to port (Guam, Yokosuka, or Wake Island), reloaded, then moved forward again and hunted. Doing this cycle as quickly as possible was important because the number of submarine squadrons was limited during the early phases of the conflict and their contribution was so significant. Submarines were also needed to screen against Chinese submarines exiting the first island chain. U.S. submarines wreaked havoc on Chinese shipping. Given the value of submarines, acquiring more is an obvious recommendation. Most analyses of future naval force structure agree that the United States should build more attack submarines than are currently programmed. However, it is unlikely that the United States could build more than the current rate of two a year during the 2020s and early 2030s when it is also building the Columbiaclass SSBN. Indeed, even achieving two per year may be a stretch. However, the U.S. Navy should commit to funding those two per year even if shipbuilding funds get tight. The Navy should also consider keeping submarines in service longer, as it has proposed by extending the service life of some 688-class boats. The Navy should also ensure that it has reloading facilities in Yokosuka, Guam, and Wake Island. Forcing submarines to go back to Pearl Harbor to reload wastes valuable hunting time. Because China will likely target fixed facilities, mobile reloading from civilian ports should be practiced. The Navy also needs to ensure that it has enough torpedoes. Although the game did not model this munition, there is reason for concern. The historical record is that many torpedoes will miss or malfunction, some will be lost when the submarine carrying them is sunk, and others will be destroyed when shore facilities are attacked. Finally, investment in unmanned underwater vehicles (UUVs) should be prioritized. There is guaranteed to be some submarine attrition in a fight against China, particularly in the constrained waters of the Taiwan Strait. Each loss would be a painful blow. A Virginia-class submarine has a crew of 135 and costs roughly $3 billion. While UUVs are not as capable as attack submarines, they could be programmed to fulfill some relatively straightforward missions (e.g., minelaying).

Procure sufficient stockpiles of standoff anti-ship weapons.
Munitions usage was high. In the three to four weeks of conflict, U.S. forces usually expended about 5,000 long-range precision missiles, primarily JASSMs and LRASMs. The United States expended its global LRASM inventory within the first few days in all scenarios. JASSM inventories were large enough that they did not run low until the third or fourth week of the war. In games where the JASSM-ER has maritime strike capabilities, the abundance of U.S. munitions made U.S. strategy an almost uncomplicated exercise. With each squadron of 12 bombers carrying around 200 stealthy, standoff ASCMs, the United States could rapidly cripple the Chinese fleet and leave the invasion force stranded. For this reason, many studies that look at this problem recommend expanding the arsenal of anti-ship weapons. However, as discussed in the assumptions chapter, the JASSM-ER might not have this capability.

Prioritize sustainment of the bomber fleet over fighters.
Both bombers and fighter/attack aircraft played important roles. However, the range and high ordnance throughput of bombers presented the Chinese with a particularly daunting challenge. The range of bombers meant that they could be based beyond the range of Chinese ballistic missiles, while their ordnance throughput meant that they could rapidly attrite Chinese forces. When paired with standoff munitions, even unstealthy “bomb trucks” are extremely useful against targets at the edge of the Chinese air defense zone.
This combination of platforms with long-range precision munitions is viable because this air campaign focuses on a few hundred aiming points comprising ships, air bases, and ports and airfields. It is not a strategic bombing campaign involving tens of thousands of aim points on the Chinese mainland and designed to paralyze the economy, military command structure, and political operations. Long-range precision missiles are too expensive to be procured in the numbers necessary to prosecute such a campaign, as the Russians are finding out in Ukraine. Further, as noted earlier, such a campaign raises questions about escalation.

Procure more, cheaper fighters.
With so many aircraft lost early in the conflict, the Air Force risks running out of aircraft and becoming irrelevant to the conflict unless it has a large enough force to sustain the losses. Therefore, the Air Force should be cautious about taking its “divest to invest” strategy too far. Numbers matter. Throughout the campaign, even fourth-generation fighter/attack aircraft had value. For many missions (such as launching standoff weapons), the stealth of fifth-generation aircraft is not needed. This was particularly true later in the conflict when Chinese air defenses weakened. At the same time, losing all fifth-generation aircraft early was a problem. After the long-range LRASMs were gone, fifth-generation aircraft were particularly valuable because they could press in to deliver shorterrange JSMs or JSOWs. There is therefore a strong argument for keeping a balanced mix throughout by withholding fifth-generation aircraft until the Chinese missile inventory is depleted. Ninety percent of aircraft losses occurred on the ground. The vulnerability of aircraft on the ground raises questions about U.S. plans to procure relatively small numbers of extremely capable but expensive aircraft. If most are lost on the ground before they can bring their advanced capabilities to bear, then cheaper airframes might be worthwhile. Plans to procure the Next Generation Air Dominance fighter, with a cost per airframe of “‘multiple’ hundreds of millions” of dollars, do not make sense if 90 percent of U.S. and Japanese aircraft losses occurred on the ground.