Over 600 marines, sailors and airmen from Finland, Germany, Italy, Netherlands, Sweden and the United States conducted training in Syndalen, Finland, which included live fire training with mortars and light machine guns. (U.S. Navy photo by Mass Communication Specialist Seaman Alyssa Weeks/Released).

One hundred and one years ago, a great power released a new weapon on the world. They allowed it to sidestep its adversaries’ military advantages and deal them a near-crippling blow. Those weapons, the U-boats of the German Empire, used new technologies to blockade the British Isles and sink millions of tons of Allied shipping. Eventually, the Royal Navy prevailed, but the outcome of that battle was never a foregone conclusion. It took the development of an array of new antisubmarine technologies and tactics, as well as a massive mobilization of resources, that enabled the Allies to win this “First Battle of the Atlantic.”

Seventy-six years ago, the Second Battle of the Atlantic began. Again, German U-boats threatened the Allies, this time with new tactics and technologies based on experiences in the previous war. The Germans had learned how to overcome the antisubmarine warfare (ASW) advantages of the Allies, and only by again bringing new technologies, tactics, and resources to bear did the Allies prevail.

During the Cold War, our ASW forces engaged in a constant cat-and-mouse game with the Soviet Union’s submarines. Nuclear power, ballistic and cruise missiles, and quieter systems empowered Soviet submarines in troubling ways. To respond, the United States and its allies were forced to build greater and more effective ASW forces and continually refine their own ASW technologies and doctrine to counter the Soviets. In the shadow of nuclear deterrence, the stakes of this competition were as high as could be imagined. This was the Third Battle of the Atlantic, and, although it was not a shooting war, it showed once again that a responsive, adaptive, and forward-deployed ASW force is necessary to deter aggression against our nation and its allies.

In the early 1990s, the end of the Cold War, the collapse of the Soviet Union, and commentary such as Francis Fukuyama’s landmark essay “The End of History?” led us to believe that our strategic rivalry with Russia and our need to stay one step ahead of Russian capabilities had faded. It has not. Once again, an effective, skilled, and technologically advanced Russian submarine force is challenging us. Russian submarines are prowling the Atlantic, testing our defenses, confronting our command of the seas, and preparing the complex underwater battlespace to give them an edge in any future conflict. Vice Admiral Clive Johnstone, Royal Navy, the head of NATO’s maritime forces, noted recently that his forces report “more activity from Russian submarines than we’ve seen since the days of the Cold War.” Some analysts believe that even our underwater infrastructure—such as oil rigs and telecommunications cables—may be under threat by these new and advanced forces. Russian focus, investment, and activity in the undersea domain are now so unmistakable that even the head of the Russian Navy, Viktor Chirkov, has admitted that Russian submarine patrols have grown 50 percent since 2013.

Despite the economic crisis in Russia, rubles continue to flow into the development of Russian submarine technology and the growth of that force. The father of the modern Russian submarine force, the brilliant and highly decorated design engineer Igor Spassky, admits Russian submarine forces are expanding and advancing, and that they will be a key part of the country’s arsenal for the foreseeable future.

By 2020, the Russian Black Sea Fleet alone will receive the equivalent of $2.4 billion of investment. And these are not the submarines we faced during the Cold War. There may be fewer of them, but they are much stealthier, carry more devastating weaponry, and go on more frequent and longer deployments than before. The submarines of the Russian Federation are one of the most difficult threats the United States has faced. This threat is significant, and it is only growing in complexity and capacity.


Russia’s New Approach

Not only have Russia’s actions and capabilities increased in alarming and confrontational ways, its national-security policy is aimed at challenging the United States and its NATO allies and partners. For example, the new Russian national security-strategy depicts the United States and NATO as threats to Russian security and accuses us of applying “political, economic, military, and information-related pressure” on Russia. Thus, not only is Russia pursuing advanced military capabilities (especially in the underwater domain) that enable it to be a credible threat to us, it is now boldly saying that it intends to act as one.

An enduring objective of Russian foreign policy today is to challenge NATO and elevate Russia on the European stage once again. Building on the national strategy, the new Russian maritime doctrine reorients its naval forces in a calculated and determined way. By confronting NATO at will, Russia confirms its status as a great power in the 21st century. The new maritime doctrine tells us that Russia will counter our existing ASW technologies; challenge U.S. and NATO’s maritime presence in the Atlantic as well as the Baltic, Black, and Mediterranean seas; and expand Russian permanent presence in the Arctic and Mediterranean.

Furthermore, Russia is rapidly closing the technological gap with the United States. It has created an advanced military designed to overcome our advantages and exploit our weaknesses—this is the epitome of asymmetric warfare. Nowhere is this more evident than in the maritime (and especially underwater) domain. Russia rapidly is building and deploying more advanced and significantly quieter attack submarines and frigates armed with the long-range Kalibr cruise missile (including six new Kilo-class diesel-electric attack submarines destined for the Black Sea). Not coincidentally, these are the platforms that are the most challenging for us to deal with because of their inherent stealth. As demonstrated last December by Kalibr launches into Syria from the Eastern Mediterranean, Russian leaders will use such weapons at will, without the same qualms we have about collateral damage. The clear advantage that we enjoyed in antisubmarine warfare during the Cold War is waning. Russian submarines are more capable than before, and so we are again in a technological arms race with Russia.

Russia is claiming maritime battlespace across Europe and deploying forces outside Russian borders. An interlocking system of Russian coastal missiles, interceptor aircraft, air-defense systems, surface ships, and submarines now threatens all maritime forces in the Baltic, as well as our NATO allies in Lithuania, Estonia, and Latvia—who no longer control even their own coastlines unless Russian leaders allow them to do so. A similar anti-access/area-denial (A2/AD) “fortress” was constructed in the Black Sea after Russian forces invaded Ukraine and seized Crimea. Russian forces deployed to Syria are growing steadily, and Russia has constructed military bases in the Arctic, militarizing and claiming large swaths of it, in contravention of customary international law. In this way, Russia has blunted our power-projection capabilities through A2/AD and extended its influence far beyond its borders.

Russia now employs an “arc of steel” from the Arctic through the Baltic and down to the Black Sea. Combined with extensive and frequent submarine patrols throughout the North Atlantic and Norwegian Sea, and forward-deployed forces in Syria, Russia has the capability to hold nearly all NATO maritime forces at risk. No longer is the maritime space uncontested. For the first time in almost 30 years, Russia is a significant and aggressive maritime power.

In his extensive academic research on naval innovation, Owen R. Cote, Jr., of the Massachusetts Institute of Technology’s Strategic Studies Program has long warned of a potential “fourth battle” for control of the undersea domain. It is now clear that a fourth battle is not looming, but is being waged now, across and underneath the oceans and seas that border Europe. This is not a kinetic fight. It is a struggle between Russian forces that probe for weakness, and U.S. and NATO ASW forces that protect and deter. Just like in the Cold War, the stakes are high.


Winning the Fourth Battle Today

With our allies and partners in NATO and across the globe, we present a broad and united front against any potential Russian threats. Our maritime partnerships yield a global network of navies that together form the greatest maritime force for peace ever known. NATO exercises demonstrate our unity superbly. For example, on 7 June 2015, 17 nations, with 49 ships, more than 60 aircraft, and a vast array of ground forces, demonstrated their abilities to operate together to defend the Baltic region in BALTOPS. This exercise, in its 43rd year, made it clear that the United States, NATO, and partner nations have an unwavering commitment to protect themselves by acting in concert. Similarly, Sea Breeze 2015 sent a clear signal to Russia that the United States and its allies will not back down in the Black Sea region. Eighteen ships from 11 nations (Bulgaria, Germany, Greece, Italy, Moldova, Romania, Sweden, Turkey, Ukraine, the United Kingdom, and the United States) demonstrated the will and ability to operate together to achieve maritime security and conduct air defense and antisubmarine warfare in the Black Sea.

A variety of policy and resource shifts have been enacted that signal our resolve to Russia. For example, the U.S. Navy’s revised Cooperative Strategy for 21st Century Seapower notes the critical importance of all-domain access and deterrence. The Chief of Naval Operations’ recent Design for Maintaining Maritime Superiority puts the Navy on a clear path to adapt to the new global security environment. But we must act now to implement such guidance before Russia provokes again. To do so, we must engage and conduct operations forward more deliberately, more strategically, and with more forethought—and in ways that encourage responsible behavior by Russia while still deterring Russian belligerence.

From a diplomatic perspective, we can find areas of common interest. One of the most obvious examples is maintaining safety at sea. Despite the recent aggressive “buzzing” of the USS Donald Cook (DDG-75) in the Baltic by a Russian Su-24, the incidents-at-sea (INCSEA) agreements with Russia remain a heartening example of how we can still cooperate with Russia despite its leadership’s adventurism. We also share a desire to defeat violent extremist organizations such as ISIS. We must be prepared to work with Russian leaders if they want to collaborate responsibly on these or other issues of mutual interest. To do so, we can and should meet with our Russian counterparts when possible and prudent. Track-two diplomatic efforts, international symposiums, and other forums that provide such opportunities should also be encouraged.

Of course, diplomacy alone is unlikely to be sufficient. To encourage responsible behavior by Russia we must engage from a position of strength, not weakness. Improving our current force posture in Europe will demonstrate our strength and thereby deter Russia from further adventurism. The first step in improving our force posture is to leverage allied navies to enhance our maritime security. We must work directly with our NATO partners to help them develop the capabilities and capacity to operate seamlessly together and with the United States, respond to contingencies, and protect key maritime infrastructure. Through combined exercises and maritime presence, a network of navies in Europe and across the globe can face Russia from a position of strength and ensure continued peace. Our part in supporting these efforts has been clearly outlined by CNO Admiral John Richardson: We must “prioritize key international partnerships through information sharing, interoperability initiatives, and combined operations [and] explore new opportunities for combined forward operations.” The old saying “a house divided cannot stand” is more true now than it has been in many years. To preserve peace, we must unite to deter Russian aggression.

We also should reassess our own global force deployments and exercises. Additional submarines, ASW forces, carrier strike groups, and other assets should be rotated through Europe and used to show Russia that we can bring overwhelming force to bear if need be. We should increase our ASW exercises with our NATO allies, in both the Atlantic, Mediterranean, and elsewhere, to demonstrate that NATO can track Russian submarines at will, no matter where they are.

Finally, we must not lose our technological edge. More than perhaps any other warfare area, ASW requires us to stay one step ahead of Russian technologies. In the world wars, the Allies prevailed over German U-boats not by force alone, but by innovation. In the Cold War, the rise of nuclear-powered Soviet submarines required us to develop new acoustic and other technologies. Today, we are once again in a technological arms race with Russia. We must maintain an innovative edge and rapidly field new technologies if we are to prevail.

At this time in history we would do well to remind ourselves it is better to prevent wars than to fight them. The U.S. Navy, through forward presence, power projection, and technological advantage, is the epitome of demonstrating resolve and capability in the service of war prevention. In today’s world, wars can only be truly prevented in partnership and cooperation with other nations. The stronger and more resolute we and our allies and partners are together, the less likely that war will occur. And therein lies the true strength of the U.S. Navy—it is not simply by maintaining our technological edge and our readiness to impose unacceptable costs on Russia should the need arise. What makes ours the world’s greatest and most effective navy is the fact that we act in concert with our NATO allies and partners. It is only in this way that we, and all like-minded allies and partners, maintain peace—by unmistakably and constantly deterring Russian aggression.