Written in Black and Red: Asymmetric Threats and Affordable Unmanned Surface Vessels


The Houthi rebels and the Ukrainian military share a significant amount in common despite very different perceptions of their legitimacy. The Houthis have held civilian and military ships at risk in the Red Sea, causing the rerouting of commercial shipping and prompting the U.S. State Department to consider them a terrorist organization. Ukraine, by contrast, is viewed as a heroic front-line state standing against an unprovoked Russian invasion. With Western aid and rapid innovation, the Ukrainian military, although by mostly cobbled-together, ad hoc means, has rapidly employed commercially available drones, organically developed, and fielded unmanned systems for aerial, naval, and ground attack. Despite having no naval warships of its own, Ukraine has managed to hold the vaunted Russian Black Sea Fleet at risk both underway and in port. In short, both forces have effectively utilized commercially available or inexpensively developed unmanned systems and anti-ship cruise missiles to great effect, stressing and challenging technologically and numerically superior adversarial forces in the Black and Red Seas.

Missiles are modern hardware, but explosive-laden boats are not. Their use dates back to as early the U.S. Civil War and they proved their effectiveness more recently when al-Qaeda struck the USS Cole in 2000. The methods of employing cruise missiles and lethal unmanned platforms are not complex. Defending against them does not need to be either. The U.S. Navy and its partners and allies should leverage commercial unmanned technologies to increase the survivability of afloat assets in the face of unmanned and cruise missile threats. These platforms can be found somewhere in between the robust and expensive ones currently being pursued, particularly within the unmanned surface vessel space, and the mass-produced, “cheap” options championed by the Replicator initiative.



Unmano a Mano

The successes, if only disruptive, enjoyed by the Houthis and Ukraine have demonstrated the potential of low-complexity drone and missile attacks. These will have far-reaching implications beyond the Black and Red Seas. Now the most powerful militaries in the world are pursuing both commercially available and more complex, developed unmanned systems. However, as the U.S. Navy has made clear in its plans for the teaming of unmanned and manned platforms in the future fleet, capital ships and manned militaries will not be going away any time soon. This means that the U.S. Navy will have to decide how to invest in order to both enhance its own capabilities through unmanned systems and defend against asymmetric unmanned threats posed by both state and non-state actors.

In many cases, the best way to counter a capability is with a similar capability. When considering the threat of unmanned systems in the maritime environment, it is important to examine the current use cases and how they support or enhance legacy manned platforms. Unmanned systems enhance intelligence, surveillance, and reconnaissance; lethality through target acquisition or precision strikes; logistics and supply operations; and force protection. Although many experts envision a day when war is fought between forces comprised entirely of unmanned, autonomous systems, technology and international law are not there yet. Leaders will likely continue to demand that humans make life-and-death decisions in identifying targets and releasing weapons in the near term. 

Robust — read as expensive — unmanned platforms may seem like the right direction when considering the high-end fight, but the presence of less costly lethal platforms and their demonstrated capabilities should drive a blended approach. As the recent exchanges in the Red Sea have shown, we should consider the cost of the weapon or platform that may be destroyed or damaged in engaging a low-cost threat. If systems are expensive, they are not truly attritable as the cost and time to replace them may be prohibitive in a time of strained and flat budgets. Less expensive systems produced en masse may be the more cost-effective answer based upon the prevailing circumstances of the mission requirements.  

The U.S. Navy in particular should not wholesale abandon plans for large and medium unmanned surface vessels, but it should reconsider the cost. Robust platforms range from $35 million to over $100 million each, while smaller platforms deployed by manned ships are much cheaper. Effective execution of distributed maritime operations in the high-end fight is reliant upon the enhancement of not only magazine capacity, but also the survivability of key platforms while extending intelligence, surveillance, and reconnaissance and electronic warfare capabilities and effects against adversarial forces. However, fully autonomous systems can now operate in an integrated fashion with afloat vessels in a force protection role. Akin to the fixed-wing centric loyal wingman drones, unmanned surface vessels should be designed to escort and enhance the capabilities of manned ships, especially within the electronic warfare, counter-explosive unmanned surface vessel, and integrated air missile defense realms. 

Current discussions about having unmanned systems supporting force protection are predicated on enhancing situational awareness for ground forces. This would involve having the systems fly in advance of or alongside a convoy utilizing various sensors to detect potential ambushes or improvised explosive devices. Similarly, large surveillance platforms, such as the MQ-4C Triton, provide support for maritime domain awareness to afloat commanders by detecting and identifying maritime contacts. Such methods of force protection are positioned to increase reaction time in order to enhance the response to a threat. The U.S. Navy has even planned to experiment with armed unmanned surface vessels to provide protection for ships and marines ashore. What is lacking is a platform that actively participates in defensive action on the part of the protected asset or a port.

Blocking and Tackling, Drone Style

The U.S. Navy and its allies should pursue platforms that prioritize countermeasure capabilities and physical blocking and shouldering of inbound craft in order to account for missile threats and explosive unmanned surface vessels. Lessons learned in air missile defense dating back to the Falklands War and gaps and seams identified in current defensive systems make a strong case for equipping an unmanned system with physical and electronic countermeasures to enhance soft kill capacity and capability while maintaining lower cost and a smaller footprint for an escort unmanned surface vessel. Soft kill tactics remain more effective in terms of both success and cost. An attritable platform that can employ soft kill and physically intercept inbound surface threats, explosive unmanned surface vessels, or suspected pirates that is small enough to load out on a variety of military and civilian vessels would present a cost-effective mitigation of the asymmetric drone and missile threat. Beyond defense of ships at sea, the escort unmanned surface vessel could provide critical capability that can be scaled and distributed to various sea ports of debarkation to enhance the defense in depth of civilian port authorities and deployed port security units, whether U.S. Navy or Coast Guard.

A escort unmanned surface vessel could be outfitted with a version of the Mark 36 Super Rapid Blooming Off-board Chaff launcher preloaded with an approved mix of six chaff rounds designed to interface remotely or autonomously in conjunction with the electronic warfare suite of its assigned warship. The unmanned defensive escort would then be able to maneuver independently for winds to support optimal chaff employment. This arrangement would work in areas where the protected ship is constrained in its ability to maneuver, for example if it is conducting flight operations or transiting a choke point. If an unmanned defensive vessel is able to carry six rounds and the defended ship can deploy four drones, then this would double the available counter measures for an Arleigh Burke class destroyer.

Future iterations of this concept should include an embedded electronic warfare suite to enable organic signal detection and jamming capabilities. This would allow the unmanned defensive escort to defend against inbound threats and potentially seduce missiles towards it through active jamming. The low freeboard nature and limited overall size could potentially increase the escort’s probability of surviving an inbound threat missile. Through integration with shipboard sensors and organic electro-optical/infrared visual sensors, the unmanned escort, in a single unit or a group, could surround or provide a threat-axis barrier against suicide or small boat swarm groups. These sensors could enable the system to maneuver to block inbound threat. This would help buy time for the defended ship to maneuver away if it were a commercial vessel or unmask batteries and properly defend itself if it were a warship. Despite somewhat limited range and speed, a platform such as the Spyglass from Saronic Technologies, measuring approximately six feet in length, would greatly enhance the survivability of a strike group, individual ship, or unarmed supply ship.

Similarly, unmanned aerial vehicles such as helicopters provide proven technologies that, outfitted with soft kill capabilities, would also greatly enhance the survivability of a ship or ship-launched aircraft. Providing chaff capability and an emitter would bring new utility to high-endurance aerial drones, including the Shield AI V-BAT. Such a pairing would provide greater on-station availability and longer-duration countermeasure effects than current ship-launched Nulka rounds by their nature of being launched, recovered, and relaunched. When combined with an unmanned escort vessel, these countermeasure unmanned aerial vehicles would provide significant protection against surface- and air-launched threats at a fraction of the cost of legacy manned platforms.

For Warships and Beyond

Conflict in the Indo-Pacific would likely see the U.S. Navy and its allies disaggregate their forces in order to complicate adversarial targeting and enhance their own distributed lethality. However, this would leave ships with a reduced defense-in-depth capacity, dependent on their organic systems and loadout. Employing these defensive systems and/or Nulka-like drones would mitigate this operational risk and enhance the survivability of limited and expensive assets. Merchant vessels would almost certainly be targets as well, as we saw in the Tanker Wars of the 1980s, placing sealift at high risk. Such ships are not outfitted with organic self-defense systems and the U.S. Navy has already told Military Sealift Command that they cannot provide necessary escorts akin to the convoys of World War II. 

Ukraine demonstrates the dangerous capability of cruise missile and lethal unmanned platforms. The U.S. Navy and its allies should be prepared. To do so, they should explore using cheap, commercially available surface and aerial drones in a defensive role that enhances the survivability of independent warships, strike groups, and merchant freighters alike. By outfitting such platforms with physical and electronic countermeasures, afloat warships can more effectively defend themselves even when constrained in their ability to maneuver by geography or operations. Undefended ships will at least stand a fighting chance of surviving without an escort. Force protection of military, logistic, and civilian ships should expand beyond merely enhancing situational awareness and take a more active role in employing proven soft kill systems. This should be done in a rapidly deployable and scalable way that that is affordable in mass — something current platforms aren’t suited for. 



Mike Knickerbocker is a surface warfare officer in the U.S,. Navy. He previously served as a carrier strike group air missile defense officer and independent research fellow at the Clements Center for National Security at the University of Texas, Austin. He has previously written on national security and technology for publications including the Hill, the Center for International Maritime Security, 1945, the National Interest, and the Defense Post.

Image: U.S. Coast Guard photo by Operations Specialist 1st Class Jeffrey Swope II