The term Anti Access / Area Denial (A2/AD) has become noticeably more prevalent in current military documents, articles and assessments over the last two decades. However, does A2/AD constitute a new, unprecedented type of threat to NATO, or is it just a fashionable, new name for a not-so-new way of using existing military means? If it is something new, are NATO’s current military capabilities and doctrine sufficient to counter this new threat, or does A2/AD require a paradigm change in how we fight future wars?
Amongst the many facets of A2/AD, this article focuses mainly on the use of symmetric military means. Aspects of asymmetric, hybrid, and cyber warfare (or the like) are outside the focus. Neither will the article discuss the support of A2/AD tactics by purely strategic means like Intercontinental Ballistic Missiles or strategic bombers
To understand the current A2/AD issue, its implications, and why it has, in fact, a new quality, it is useful to first look at a definition of A2/AD. The role of conventional deterrence in the age of nuclear weapons, and the potential explanations for current A2/AD developments are also significantly important.
While NATO has not officially agreed on a definition ofÂ A2/AD, a 2016 conference report from the NATO Defence College proposes the following: ‘The objective of an anti-access or area-denial strategy is to prevent the attacker from bringing its forces into the contested region (A2) or to prevent the attacker from freely operating within the region and maximizing its combat power (AD).’1 This explanation seems to characterize A2/AD as mainly defensive in nature. In comparison, in 2003 the Centre for Strategic Budgetary Assessment (CSBA) defined A2/AD as follows: ‘Anti Access are enemy actions which inhibit military movement into a theatre of operations, and area denial are operations […] that seek to deny freedom of action within areas under the enemy’s control.’2 This description, offers a more aggressive interpretation of A2/AD. Overall, most A2/AD definitions agree on the defensive character of A2/AD. It has been noted that whatever definition is preferred; A2/AD capabilities might be defensive in the first place but could be employed in conducting or supporting different types of offensive operations, too.
The Emergence of AD in the West
After World War II, the United States published the National Security Council Document NC 162 / 2 announcing the tenet of ‘massive retaliatory damage by offensive striking power’, including the use of strategic and tactical nuclear weapons in response to a Soviet aggression. This was the result of the perceived overwhelming conventional threat by the Soviet Union in comparison with the assessed conventional capabilities owned by the US and ‘the West’. Later on, diverse studies demonstrated a perceived moral taboo (especially in Western politics) to use nuclear weapons, which reduced their credibility and therefore utility.3 Furthermore, nations with a nuclear arsenal may feel encouraged to attack with conventional force, by relying on their own nuclear deterrent.4 This meant that a comprehensive build-up of conventional capabilities, in addition to its nuclear arsenal, was needed for the West, otherwise an early nuclear escalation would have become inevitable for most conflicts. In the 1960s, NATO therefore replaced its previous ‘Massive Retaliation’ strategy with ‘Flexible Response’, a more balanced deterrence posture using an arsenal of conventional and nuclear forces. The premise of this strategy was to deter most conflicts by appropriate conventional force, while maintaining the nuclear option as a means of ultima ratio.
In the mid-to-late 1970s, the so called ‘Second Offset Strategy’ came to the US national side, which predominantly emphasized tactical level superior technology in the conventional arsenal. This new strategy focussed on four core areas:
- New Intelligence, Surveillance and Reconnaissance (ISR) platforms and battle management capabilities;
- improved precision-strike weapons;
- stealth technology;
- the tactical exploitation of space for ISR, communications, navigation and timing.
The US thereby strongly enhanced its capability to achieve ‘Deterrence by Denial’5 and thus added a reliable AD facet to its conventional offensive portfolio asÂ a serious force multiplier. This capability was combined with the US capability of global force projection with, for example, Carrier Strike Groups, strategic airlift, and long-range aviation enabled by air-to-air refuelling. Together, they created a dynamic, mobile ‘AD on demand’ component, which made conventional deterrence a credible substitute before threatening with the nuclear alternative.
Adversary Reaction to Western AD
In order to counterbalance this higher level of conventional deterrence and maintain military relevance outside the nuclear realm, opposing actors in the global security environment had to develop an adequate response to those new Western power projection capabilities. This required both development of new arms technology and its effective employment with regard to the geographical features of the defended area. Therefore, the characteristics of each A2/AD composition vary by nature in between theatres, pending the assessed capabilities of the potential intruding force as well as the characteristics of the regional environment.
Today, the most significant, regional A2/AD configurations are deployed in the Asia-Pacific region (China)6 as well as on NATO’s eastern and south-eastern flanks (Russia in Kaliningrad, Crimea and Syria)7, where a blend of state-of-the-art Air Defence Systems (ADS), advanced Offensive Counter-Air capabilities, powerful electronic jammers as well as the newest, most accurate theatre ballistic and cruise missiles prevents third-party military operations. Despite the fact that the effects of such A2/AD are limited to a certain region, their likely integration into overall military organizations and connection to rear areas (‘strategic depth’) has to be considered as well.
Significant Russian and Chinese A2/AD Capabilities
Russia introduced the term ‘Reconnaissance-Fire Complex’8, describing the US-owned combination of Precision-Guided Ammunition (PGM), ISR capabilities, and automated Command and Control (C2), which needs to be interrupted.
Counter ISR. Since accurate targeting information isÂ crucial for the opponent, the denial of ISR data collection is an efficient solution. This can be done by jamming sensors of land-, air-, sea- and space-based ISR assets in the whole electromagnetic spectrum (EMS). Current jammers are able to effectively deny the use of the EMS up to a range of several hundred kilometres including low-orbit satellites and means of communication for automated C2 systems. A study has shown jamming ISR satellites operating in the visual range of the EMS with laser is possible as well.9 Also, the kinetic kill of air- and space-based ISR sensors by means of Air Defence or Anti-Satellite Systems is possible. These options would deny an adversary the gathering of necessary ISR data to execute the Reconnaissance-Fire Complex.
Counter PGM. Another option is to destroy the PGM or the carrier itself. ADS can engage targets of various types and at different ranges. The Russian S-300 (SA-20 Gargoyle) or Chinese HQ-9 can provide coverage of up to 200 km, the newly introduced S-400 (SA-21 Growler), up to 400km. This, in combination with other ADS like the Russian Pantsir-S1 (SA-22 Greyhound) or Man Portable ADS (MANPADS), can deny most aircraft the reach of their weapon delivery range, rendering them ineffective while imposing a high risk of attrition. E.g., when attempting to neutralize A2/AD offset-up in the Kaliningrad Oblast, a potential aircraft attrition rate of 20 – 30 percent is estimated.10
Politico-Military Benefit of Implementing Regional A2/AD
Considering no nation wants to start a regime-changing conflict against NATO Nations, the installation of regional A2/AD zones has to be considered defensive in the first place. Hence, A2/AD’s main purpose is to prevent a potential adversary from reaching a certain military operational objective. Leaving the defender’s strategic long-range (in particular nuclear) weapon arsenal aside, the main benefit of A2/AD appears to be ‘Deterrence by Denial’ rather than ‘Deterrence by Punishment’.11
This is especially true for nations that do not possess nuclear weapons, like Iran, where regime change is a perceived threat. An implemented A2/AD zone is then merely a fortification of national defence designed to maximize attrition of the attacker. While this is an ancient principle, the availability of modern weapon systems like long-range precision-strike missiles and ADS allows a defender to have deeper coverage inside the adversary’s territory or his avenues ofÂ approach, and therefore the possibility to affect extended gradual attrition. Furthermore, the denial ofÂ precision strike capabilities increases the chance of regime survival for a longer time period.
For strong nuclear nations, like Russia or China, the threat of attacks against their territory is actually fairly low, due to their nuclear deterrent. The calculus for establishing regional A2/AD is therefore probably different. China’s A2/AD posture In the Asia-Pacific region is often called ‘Counter Intervention’12, which supports this conclusion. As for Russia, too, the concept of securing a ‘fait accompli’ situation is a more plausible rationale. This concept foresees a military plan executed close to their homeland while timely, third-party intervention is prevented until the mission is complete. Afterwards, when the third party has managed to marshal its conventional intervention force, the nuclear deterrent might serve to discourage further encroachment.
Reflections on Countering A2/AD
Ends. Why would NATO as a genuinely defensive alliance launch military operations against A2/AD structures, such as those mentioned above? Despite the fact that aggression into other countries’ sovereign territory is not acceptable in international law, ‘fait accompli’ conditions such as the Crimean Peninsula and hypothetically emerging in the Baltic NATO Nations, could bring the Alliance into situations where A2/AD bubbles need to be offensively and defensively dealt with in the early phases of an intervention. However, the defeat of an A2/AD zone can only be one objective on the way to achieving the overall mission.
Ways. Fundamentally, there are two main options for countering A2/AD. These are the Inside-Out and the Outside-In approach13. Inside-Out is based on a technological advantage which strives for a short, high-intensity conflict, hitting the A2/AD system’s centre of gravity with the factor of surprise and thus breaking the obstacle hindering the advance of friendly forces. In contrast, Outside-In chooses the potentially lengthy approach of dismantling the adversary’s capabilities layer by layer. This bears the obvious risk of higher attrition and mission fatigue, which generally is not politically acceptable in NATO, and is therefore difficult to sustain. Therefore, Inside-Out seems to be the most logical and feasible method of countering A2/AD. To be successful with this approach, the necessary military effectors must penetrate the A2AD bubble to get within their weapon engagement range. However, this is exactly what modern, highly-sophisticated A2/AD capabilities are designed to prevent. It has to be recognized these significant capabilities have most probably reduced the previous technological advantage of Western arsenals, to include the US resources for global force projection and precision strike.
Means. Consequently, NATO requires the following new capabilities:
- Stand-off strike capabilities with the range to engage from outside, or from the edge of, A2/AD zone in combination with A2/AD-resistant ISR means
- Technology that can successfully penetrate an A2/AD zone and create a desired effect
- New concepts for using existing technology
- Counter A2/AD Capability Development – US Example
In the latest ‘Third Offset Strategy’, the US laid out possible solutions to rebalance conventional deterrence in light of the A2/AD capabilities of potential adversaries. At the forefront are the ‘Global Surveillance and Strike Concept’ (GSS)14, the ‘Air Force’s Global Strike Task Force’15, and ‘Conventional Prompt Global Strike’ (CPGS)16. A 2010 study from the for Strategic and Budgetary Assessments (CSBA) depicts some elements of a potential long-range strike family.17 Herein, new standoff munitions are being described which could defeat A2/AD strategies. For example, advanced tactical cruise missiles with a range around 500NM orÂ super-/hypersonic missiles with a range of up to 1000NM could overcome the time / distance limitation of existing subsonic weapons. Also, the development of conventional long-range ballistic missiles, with new supersonic warheads based on the Navy’s Trident or the Air Force’s Minuteman II or Peacekeeper BM, are mentioned as a way to ensure global conventional strike capabilities. Another proposed technology, which would bring a new quality to the arsenal is a ‘New Penetrating Bomber’. This asset should have, amongst others, the following abilities:
- Manned or unmanned
- Unrefuelled range of at least 4000NM
- Broad-band, very low observability
- On-board surveillance and self-defence capabilities to permit independent operations against fixed and mobile targets in degraded C4ISR environments
This would allow this airframe to operate independently in an A2/AD environment with a significant probability of success. Subsequently, air superiority could be increased and temporary control of the air space achieved in order to start the Inside-Out approach.
Since the current US airframes for electronic warfare (EW), like the Growler, Prowler or EC-130H lack the required range, persistence and survivability to handle modern A2/AD environments, the study17 recommends a new ‘Airborne Electronic Attack’ Platform (AEA) designed to handle modern A2/AD systems.
Counter-A2/AD Employment / Deployment Concepts
In reaction to the Ukraine crisis, NATO invoked the Readiness Action Plan (RAP) which enhanced theÂ NATO Response Force (NRF) Concept with the Very High Readiness Joint Task Force (VJTF) and procured the review of Graduate Response Plans (GRPs) in order to reassure Allied Nations. When these plans are executed, adversary A2/AD will target the forces deploying into the theatre. Therefore, NATO will have to achieve certain effects within the A2/AD zone to temporarily generate a favourable air, ground, or naval situation that allows starting the Inside-Out Approach. If this effect cannot be generated from outside of an A2/AD zone, the necessary capabilities need to be already in place (pre-deployed) to create favourable circumstances.
In the example of the Kaliningrad Oblast, a significant amount of Russian ADS create a hostile air space that reaches deep into NATO territory. Furthermore, land-based, anti-ship cruise missiles pose a severe A2/AD challenge to NATO maritime forces far into the Baltic Sea. Pre-deployment of adequate EW equipment (ground-, sea-, or air-based) in operational range to Kaliningrad could generate instant effects allowing for relatively protected mobility. Also, the use of Special Operations Forces could be very effective and precise, however, longer mission preparation and fill-in times would have to be calculated.
In essence, countering A2/AD has to be considered a joint force challenge requiring mission planning and coordination above single-service command levels and the combination of various tactical capabilities across the joint force. Based on experience in the Asia-Pacific arena, this issue has already been addressed in US Concepts such as ‘Joint Concept for Access and Manoeuvre in the Global Commons’; formerly known as ‘Air-Sea Battle’. The latter outlined solutions to combine and integrate existing capabilities from the services jointly in order to enhance the probability of success against concentrated A2/AD areas.
Despite A2/AD being prevalent in current studies and discussion, it is principally not a new threat. The notion that it significantly changes the way military capabilities are being used is also untrue. It is a mere logical consequence of the conventional arms and technology race which has been ongoing since the end of WWII. Simply put, A2/AD is the response to western force projection, precision strike, and highly-networked C2 capabilities. Greatly advanced features, such as extended detection and engagement ranges in combination with high mobility, low detection probability, and networked redundancy, have created new defence capabilities that need to be addressed. Since attrition warfare must not be the first option for NATO, technical solutions and creative concepts have to be found to assure future mission success. Specific counter-A2/AD capability gaps need to be clearly identified and filled by robust and appropriate means to maintain an acceptable level of conventional deterrence. This must take the immense technological innovation speed of our adversaries into account, demanding faster and more adaptive development and procurement procedures. Also, NATO doctrine should be reviewed in order to reflect the highly integrated joint and combined processes needed in countering A2/AD.