Run Silent, Not Deep

The contest for control of the seas will also take place in the information and space domains and across the [electromagnetic] spectrum. Maintaining resilient command and control, communications, computers, cyber, intelligence, surveillance, reconnaissance, and targeting (C5ISRT) architecture has never been more vital.

—Chief of Naval Operations (CNO) Admiral Michael M. Gilday, CNO NavPlan January 2021

Future naval combat will be high-speed, lethal, and complex. Beyond-line-of-sight technologies have created new challenges in high-end naval warfare, including space-based sensors and antiaccess/area-denial shore-, air-, and sea-launched missiles, drones, and loitering munitions. The development and continuous improvement of sophisticated over-the-horizon (OTH) weaponry has significantly expanded the size of the battlespace and improved shore-based forces’ ability to project power across and beyond the sea. Hypersonic and ballistic-missile technologies, such as China’s DF-21 and DF-26 missiles, increase the pace of warfare and reduce defensive reaction times.¹ Concurrently, the proliferation of cheap precision drones with small warheads, such as Iran’s Shahed 136, increases war’s asymmetry.² As Admiral Gilday states, “We have to do more than simply employ new capabilities—we must compete in new ways.”³ Future naval warfighters need to adopt new tactics if they want to win.

The Ukrainian Navy has creatively used both cruise missiles and drones to strike Russia’s Black Sea Fleet surface combatants.⁴ Such threats will only increase in the future as the United States, China, Russia, North Korea, and India are all investing in hypersonic missile development.⁵ It seems just about everyone is investing in drone technology. These future threats will define the physical battlespace; electronic warfare enables them, but it also can be used to counter them.

Effective Targeting

The threat of OTH weapons is significant, but OTH weaponry depends—as all fires do—on effective targeting. The shooter must be able to find, fix, and range the adversary to successfully engage it. In the past, an adversary could often be seen before it could reach engagement range. In the 1987 Iraqi attack on the USS Stark (FFG-31), the Iraqi aircraft was detected nine minutes before the first missile launch.⁶ In the HMS Sheffield sinking during the Falkland Islands War, the Argentinian aircraft was detected on radar 19 minutes before the missile strike.⁷

Soon, an engagement radius may exceed the organic sensor range of both target and shooter. As Joint Publication 3-85 notes, several electronic warfare (EW) capabilities could become critical to OTH targeting. This fundamental change depends on interconnected platforms, joint electromagnetic spectrum operations, and EW. For example, detection and exploitation depend on passive radio frequency (RF) collection to locate and identify threat systems. And precisely geolocating threats for countertargeting requires improving detectors and networking multiple sensors together.⁸

RF transmitters are like flashlights in the dark: The light illuminates only a small part of the environment but is seen by everyone in the area.

It obviously is a bad idea to conduct close naval combat at night with decks illuminated; sailors “darken ship” for a reason. Unrestricted use of the EM spectrum, especially against peer competitors, similarly exposes a force and does the adversary’s targeting work for it. For this reason, emission control (EmCon) may be the most important defensive tool to break an adversary’s detect-to-engage sequence and defend against the OTH threat.

OTH targeting can make every engagement an ambush. It gives to those with the capability the power to out-range their adversaries. In the future, naval warfare often will be fought beyond line of sight, relying on coordination with space, shore, and air forces across a wide area, linked through the EM spectrum to mass fires. Having realized how essential integrated sensors and platforms will be, the Navy has begun implementing the distributed maritime operations (DMO) concept and initiated integration into the joint all-domain command and control (JADC2) construct with Task Force Overmatch.⁹ These initiatives require platform integration across the electromagnetic spectrum, generating warfighting advantage by providing naval warfighters the ability to synchronize effects. But more will be required to fight on tomorrow’s battlefield.

A former OpNav N2 analyst, Richard Mosier, writes that DMO depends on naval forces being hard to find, hard to kill, and lethal. He points out that the Navy has been investing in the hard-to-kill and lethal tenets but is lacking at hard-to-find.¹⁰ The Navy’s newer acquisitions suggest it has been attempting to achieve the hard-to-find criteria by incorporating stealth and low-observable technology in platforms such as the DDG-1000 and the F-35.¹¹ This makes sense in terms of traditional naval combat, in which active radar sensors acquire targets to develop tracks that can be fired on.

But EW enables passive ways of finding targets. On the future battlefield, sloped angles and radar-absorbent materials will not be enough to hide from adversary missiles. To be hard to find, ships and warfighters must control their emissions, forcing themselves into a signals-restricted environment to avoid passive detection and OTH targeting. Fortunately, the Navy already has considerable experience with an entire category of vessels that operate in a signals-restricted environment and that can be used to guide thinking about the future of EW-dependent warfare: submarines.

EmCon Déjà Vu All Over Again

The U.S. submarine force depends on passive-sensor-only operations. Emission control—specifically acoustic emissions—is daily business, essential to submarines’ tactical utility. Sailors wear sneakers and runners wake up the next watch in person, all to avoid unnecessary noise. Submarines seldom employ active sensors: Active sonar alerts adversaries to a submarine’s presence; “going active” is risky. Success under the sea depends on submarines understanding their operating environment, acting with initiative, and prioritizing stealth. Tomorrow’s surface warfighters will be forced to view operations above the sea in a similar fashion. Ships and aircraft will employ EmCon to control their noise within the RF rather than audio spectrum.

The submarine force goes to great lengths to understand its operating environment at each moment. Environmental conditions affect sound propagation, which is essential to understand when placing sensors, conducting combat operations, and maneuvering.¹² Like sound waves, electromagnetic waves propagate in a fairly predictable fashion that depends on atmospheric conditions, geography, weather, season, and time of day, among other things. Tomorrow’s naval warfighters will need to understand the “geography” of the RF spectrum within the battlespace—the electromagnetic operating environment (EMOE).¹³ As with submarines and acoustic conditions, understanding the EMOE can inform optimal sensor deployment and aid in the planning for and execution of force maneuvers and combat operations. It could prove worthwhile to develop EMOE processes analogous to those the submarine force uses.

The submarine force often must operate with limited access to direction from higher headquarters, relying on initiative and mission command to carry out its tasks. Future surface warfighters will likewise be operating in a self-imposed degraded or denied communications environment to avoid providing the adversary with targeting information. Units operating “under the guns” of the adversary will need to operate by commander’s intent, making do with low-bandwidth and receive-only systems. Surface and air communities likely will benefit from adopting initiative-based principles that trust and empower deployed commanders to act decisively and independently. At the same time, shore-based commanders can broadcast in the blind to pass updated tasking and direction to deployed ships operating in restricted emission conditions. Developing robust shore-side command, control, and communications processes and infrastructure similar to those of the submarine force could enable ships to operate while remaining RF-quiet.

Submarines are designed from the ground up to be acoustically quiet, and skilled officers and crew operate them to minimize acoustic signatures. This makes the U.S. submarine force the most lethal maritime force on the planet. Future ships and aircraft can gain advantage by similarly making extensive use of passive sensing technologies and low probability of detection radios designed to be RF-quiet. In addition to better design, the officers and crews who fight these future platforms should be trained in EW operations. Drones, aircraft, designated picket ships, and other remote sensors could operate actively, broadcasting sensor information over one-way datalinks and protecting most of the force from detection and targeting.

Submarines have the advantage of having always operated in an environment in which passive detection is preferred to active sensors. The force’s culture and processes have been developed over its history and are ingrained in how it operates. Learning to fight on and above the surface in similar fashion will likely be difficult, and additional challenges are certain. But in the end, the Navy, its crews, and its commanders will be better for it.

Seeking Advantage

Fundamentally, naval warfare is a contest between sailors using the tools provided to achieve warfighting superiority over an adversary. Each tool has advantages and disadvantages. Electronic warfare is one more tool, which will grow in importance as technology evolves. It will be an important component of future combined arms warfare, but, like any other weapon, there are dangers when EW is misemployed.

Against a peer competitor, the improper use of the electromagnetic spectrum would not merely limit a warfighting advantage; it could provide the adversary valuable information. It is imperative to rethink how to operate and employ forces in light of the positive and negative possibilities EW brings to the battlefield. That rethinking should incorporate appropriate lessons from other warfare areas to build a more effective future fleet. Naval commanders will be tasked to fight within the electromagnetic spectrum by mastering its methods and tools of war, or they will risk being outflanked in the multidomain battlespace.