Key point: These new high-tech destroyers are overengineered. They might have some advantages, but they aren't the finest ships ever made.
The USS Michael Monsoor, second of the Zumwalt-class destroyers, recently embarked on trials and will be delivered to the U.S. Navy in the next year. While neither the Monsoor nor its older sister Zumwalt are likely to be ready to contribute to a war on the Korean Peninsula in the near future, the crisis show no signs of abating. As tensions between the United States and North Korea grow, it’s worth asking what role the largest, most lethal destroyers in the U.S. arsenal might play in the conflict.
The Last War
In the first Korean War, the United States Navy used all four of its Iowa-class battleships, along with several gun-armed heavy cruisers, to bombard North Korean positions along the coast. This usage built upon the Navy’s experience during World War II, when heavy-gun-armed ships engaged in fire support during amphibious operations, and bombardment against Japanese coastal installations. While the operations against Korea were regarded as successful, they were not decisive; the Iowas could not strike at sufficient depth to disrupt Chinese and North Korean logistics. Still, the concept of attacks from the sea against land targets were deeply compelling to U.S. planners, as the U.S. Navy generally expected to have command of the sea.
After the 1991 Gulf War, the U.S. Navy decommissioned its last battleships. The U.S. Marine Corps, among others, argued that the United States still needed gunfire support for amphibious operations, and platforms for long-range attacks against targets in the littoral. The Zumwalt class was conceived in response to this need, as the Navy sought a land-attack warship that could operate with minimal support to disrupt and destroy advancing enemy formations. The keys to this capability were a stealthy design that would preclude attacks against the ships from aircraft and coastal missile installations, a large magazine of land-attack cruise missiles, and the Advanced Gun System, which could theoretically hurl 155-millimeter shells up to eighty miles with tight precision and a high rate of fire.
The Zumwalts have since been tasked with an antiship mission, in part because of changes in the strategic situation, and in part because of procurement difficulties associated with munitions for the Advanced Gun System. Unfortunately, the LRLAP (long-range land-attack projectile) that could strike at advancing columns and defensive positions deep inside North Korea was canceled, due to excessive cost. This has had the effect of limiting the potential effect of the AGS to coastal areas, depending on how the Navy finally determines to equip the system.
Still, within a couple of years the Zumwalts could well be equipped with the Excalibur munition, which has an effective range of about thirty miles. This would give the Zumwalts a deeper punch than the Iowas, with the ability to hit targets with ten rounds per minute from each of their two 155-millimeter guns. The combination of precision and high rate of fire could give any North Korean formations unlucky enough to find themselves under attack an extremely bad day, especially given advances in precision laser-targeting for artillery projectiles. When fully integrated, each destroyer could carry over a thousand projectiles.
The Zumwalts also have an eighty-cell vertical-launch system, enabling them to carry cruise missiles for attacks against North Korea targets. Of course, the U.S. Navy already has extensive cruise-missile attack capabilities, but with the Zumwalts operating in the North Korean littoral, the missiles could strike with relatively little warning. A network of sensors would provide targeting data for the missiles, allowing Zumwalt and Monsoor to maintain their low, stealthy profile.
The Enemy Gets a Vote
It is unclear how effective North Korean coastal defenses would be against the Zumwalts. The destroyer’s stealth characteristics are intended to make it difficult for North Korean missiles to lock, although of course the ships would still be subject to visual identification. It’s also likely that U.S. attacks on North Korean sensor and recon assets would limit the ability of DPRK forces to successfully locate and target the destroyers. Some of the VLS cells on the Zumwalts would undoubtedly carry point-defense surface-to-air missiles designed to destroy aircraft and cruise missiles. The Zumwalts would also use electronic countermeasures to prevent North Korean missiles from successfully locking on. With a high likelihood of overwhelming U.S. air dominance, North Korean aircraft would be hard pressed to find or attack the Zumwalts in any case.
The bigger threats would come from mini subs, small boats and mines. North Korea has an extensive fleet of submarines, and the United States probably could not destroy all of these in the opening days of the conflict (although sub bases might be one of the first targets for the Zumwalts). These submarines would struggle to locate the Zumwalt or Monsoor, but might get lucky, and would be difficult to find and destroy before they attacked. North Korea may also lay minefields in the areas that the Zumwalts are likely to patrol, making it hazardous for them to operate with extensive support. Small boats, responding to reports of heavy shellfire and sailing from civilian port facilities, might pose the greatest threat; they could find the Zumwalts and attack with a variety of small munitions, or themselves. The destroyers have thirty-millimeter cannon would provide point defense against swarms of small boats, but would still come under substantial threat.
That said, the Zumwalts are very large and very expensive, and it’s unclear how willing the United States would be to operate them in potentially dangerous situations. Including the Zumwalts in a classic task force, with antisubmarine and antiaircraft escorts, would reduce their operational effectiveness while securing them from attack. Nuclear submarine escorts would allow the Zumwalts to maintain their stealth, but such subs would have difficulty in the littoral areas where the Zumwalts excel.
The Zumwalts were designed to destroy an army like North Korea’s: heavy, mechanized columns advancing under the protection of surface-to-air missile systems that limited the effectiveness of air attacks. If war breaks out on the Korean Peninsula, some of the combat will almost certainly match this plan, making the Zumwalts the perfect platform for land attack. The delivery of huge amounts of ordnance along coastal roads and against coastal installations would undoubtedly disrupt North Korean expectations.
It remains to be seen, however, whether the Navy would actually commit its most expensive surface-warfare vessels in dangerous situations. The Navy’s SSGN force can do some of the same job, minus the Advanced Gun System. And the United States will likely have air supremacy from the early hours of any conflict against North Korea. Still, even if the Navy decides not to take advantage of the unique capabilities of the Zumwalts, they can contribute cruise missiles and long-range gunfire to the suppression of the North Korean military as part of task forces.
Robert Farley, a frequent contributor to TNI, is author of The Battleship Book. He serves as a Senior Lecturer at the Patterson School of Diplomacy and International Commerce at the University of Kentucky. His work includes military doctrine, national security, and maritime affairs. He blogs at Lawyers, Guns and Money and Information Dissemination and The Diplomat. This first appeared in 2017 and is being reposted due to reader interest.