Editor’s Note: Readers will be aware of the latest tensions surrounding NATO following recent U.S. statements on tariffs and alliance commitments. This article was drafted and edited before those developments emerged, and therefore does not address them directly.
In August 2025, NATO published the second edition of the Allied Joint Doctrine for Security Force Assistance (AJP 3-16). This document substitutes AJP 3-16 edition A, which was published almost ten years ago. The international security environment has significantly changed since that moment.
During the summer of 2021, Western troops returned from Afghanistan where the Afghan National Defense and Security Forces (ANDSF) disintegrated in face of a major Taliban offensive. This moment showcased that twenty years of NATO’s Security Force Assistance (SFA) proved to be futile despite massive investment. Just a few months later, in February 2022, Russia invaded Ukraine. Western states shifted their focus from expeditionary missions overseas to enhancing European security and collective defense. At the same time, several states in the Sahel region terminated military agreements with their Western partners, instead forging alliances with Russia and China, highlighting their growing Security Force Assistance goals and capabilities in a context of strategic competition. These developments, among others, cultivated several lessons for Security Force Assistance. This article highlights the most interesting revisions to AJP 3-16, linking these to the developments and accompanying lessons from the past decade.
The Changing Character of Security Force Assistance
Whilst in the past two decades, SFA has mainly been deployed to enhance counterinsurgency efforts in the context of irregular warfare, it is now also used as a strategic tool to counter conventional threats as illustrated by the Russia-Ukraine war. Consequently, the concept of SFA that was shaped during the wars in Iraq and Afghanistan also shifted in character. This is reflected in the doctrine, albeit in minor details. For instance, whilst the superseded doctrine (AJP 3-16 edition A) states that SFA can range from “improving local forces of a host nation facing a threat, to advising against an immediate threat,” the second edition specifies that it concerns both immediate internal and external threats (1.7). This change seeks to broaden the definition of SFA to include renewed SFA activities in Europe following the Russian invasion of Ukraine.
Furthermore, the latest edition includes a new section on unity of effort, which is characterized as challenging in a “competitive and multi-actor SFA environment globally” (1.13). This is an acknowledgement that SFA efforts by other actors can be potentially used as a tool in geopolitical competition to undermine NATO influence.
Iraq provides a clear illustration of this dynamic. In 2018, at the request of the Iraqi government, NATO established a non-combat advisory mission to strengthen Iraqi security institutions. In parallel, both the European Union (EU) and the United Nations (UN) also contribute to Iraqi’s security sector reform efforts, complicating coordination attempts. Perhaps more problematic is the assistance provided by Iran to some segments of the Popular Mobilization Forces. These consist of predominantly Shia militias that were instrumental in the defeat of Islamic State (IS), yet some of which are also accused of hostility against the US. Through the Popular Mobilization Forces, Iran can project influence and undermine Western SFA efforts. There are also signs of Chinese and Russian SFA activities as Iraq recently purchased the Chinese Cai Hong-5 drones and expanded military-technical cooperation with Russia.
Similar patterns of competitive, multi-actor SFA are evident well beyond the Middle East. Both Africa and the Indo-Pacific are regions where several powers are building partnerships and providing military assistance to indigenous forces to compete and deter adversaries. Oftentimes, this competition takes place over one recipient country. For instance, Mauritania, NATO’s only partner in the Sahel, also received military assistance from China in the form of training and equipment. NATO must adapt to these evolving (competitive) multi-actor environments. Importantly, NATO’s Defence and Related Security Capacity Building Initiative is based on a request-driven process. Under this framework, NATO only provides assistance to partners upon request. In addition, as the doctrine confirms, “SFA applies only where a host nation requests assistance from NATO to train and develop local forces” (1.7).
Security Force Assistance Outside the Host Nation
One clear deviation from the previous doctrine is the inclusion of SFA outside the recipient country (i.e., host nation). According to the latest doctrine, “while SFA normally occurs within a host nation, NATO may conduct SFA outside the host nation, such as a NATO owned training site” (1.3). To minimize strategic risks and avoid a direct war with Russia, Western armed forces train Ukrainian recruits through bilateral and multilateral programs out of theatre. Examples include Operation Interflex in the United Kingdom and the European Union Military Assistance Mission Ukraine in Germany. The headquarters of the NATO Security Assistance and Training for Ukraine (NSATU) is also based in Germany, but training sites and logistical hubs are spread across Allied countries. This differs from, for instance, the British-led Operation Orbital that was implemented after the Russian annexation of Crimea in 2014 to provide training within Ukraine’s borders.
Improving Security Force Assistance Capabilities and Assessment
The latest doctrine also contains additions that indicate the incorporation of lessons learned since the previous doctrine was published. One major improvement is the section on assessment which not only significantly expanded but also contains a local force assessment tool that consists of an institutional, organizational, environmental, and operational compartment (2.21). Twenty years of SFA in Afghanistan taught practitioners that previous assessment tools used by the coalition failed to assess the effectiveness of the ANDSF. These were focused on measurable outputs such as the number of personnel—thereby creating, as the report by the Special Investigator General for Afghanistan Reconstruction (SIGAR) states, “a misleading picture of Afghan National Army readiness.” According to Jahara Matisek and William Reno, the focus on metrics is a symptom of a larger problem: strategic disintegration. SFA has often been used as a tactical tool that is disconnected from strategic objectives. The expansion of assessment in the latest doctrine is therefore a reflection of lessons learned from the missed opportunities in Afghanistan.
Interestingly, not only the local force must be subjected to assessment according to the document. The latest doctrine also states that “a commander should monitor and evaluate NATO forces conducting SFA.” According to John Nagl and Marshall Cooperman, “the most significant issue plaguing the early SFA mission [in Iraq] was the lack of qualified personnel assigned to serve as advisors.” The same is true for Afghanistan, where the Operational Mentoring and Liaison Teams were not staffed with specialized advisors or trainers. For instance, few noncommissioned officers and officers of the first Dutch OMLT met the initial requirements set by the commander. The lack of qualified personnel in combination with short rotations (usually six months) hampered the development of rapport between advisors and their counterparts. Therefore, the latest edition also added that “continuity of NATO leaders and trainers/advisers should be maximized to the greatest extent possible, to allow the building of relationships, trust and influence” (1.16). Extending the duration of a rotation, allowing SFA providers to (voluntarily) return for a second rotation, or permanently stationing SFA personnel overseas might require a shift in policy (one that is likely to meet resistance).
An important aspect of building rapport is cultural understanding, which can be fostered by the continuity of SFA trainers who will gain a better understanding of local dynamics when spending prolonged time in a recipient country. Compared to the previous edition, the latest doctrine contains more emphasis on cultural awareness. The new doctrine states, “cultural misunderstanding may lead to security (escalation of force) incidents and harm to civilians when culturally unknown behaviors are misperceived as hostile” (1.35).
The doctrine also pays attention to the recipients of NATO training and their cultural backgrounds such as ethnicity, morale and education (3.18). For example, it cautions that “commanders should avoid mirroring the development of local forces based on their own nation’s norms that may not be achievable, sustainable, or desirable” (1.22). This is an issue that has always existed in SFA missions and plagued both the interventions in Iraq and Afghanistan. The US designed the structure of the Afghan and Iraqi armed forces to mirror that of Western armed forces and therefore disregarded indigenous structures. Such structuring was detrimental to the ability of indigenous forces to function independently of direct NATO assistance.
Furthermore, the Special Inspector General for Afghanistan Reconstruction report pointed out that “the mandate to conduct partnered operations with the ANDSF taught the Afghans to model their fighting on that of the United States, resulting in Afghan ground forces’ increasing dependence on US-provided advanced military capabilities.” As a result, the overreliance on Western equipment and air support negatively impacted the morale of Afghan soldiers when the US signed the Doha agreement with the Taliban. Thus leading to the near-total collapse of the ANDSF after the coalition withdrew 2021.
Human Security and International Law
Whilst NATO already emphasizes the importance of cultural awareness, this new doctrine adds that “cultural practices of host nation forces may break international and national laws/norms. Commanders should consider when this cultural norm breaks a bond of trust and undermines the values of NATO” (1.32). In fact, the new doctrine contains several new references to the importance of adhering to international law, human security considerations, and NATO values. This is exemplified by the addition of a concept termed ‘Protection of Civilians.’ According to the latest doctrine, “SFA activities should contribute to the protection of civilians by strengthening the local force’s abilities to mitigate harm to civilians” and “the delivery of international law and human rights training programmes to local forces can contribute to ensure their understanding of the threat and effects of violence on the civilian population [ … ]” (1.9). A lack of civilian harm mitigation will not only lead to more violence but can also weaken the legitimacy of local forces. This was a major problem in Mali and Niger, where Western-trained security forces committed human rights violations. According to Luca Raineri, “real or perceived state abuse is the number one factor behind young people’s decision to join violent extremist groups [in the Sahel region].” The new doctrine language therefore recognizes the importance of integrating human security considerations in SFA-type missions.
The focus on human security is also visible in an added section on NATO cross-cutting topics (3.30). These include: Women Peace and Security, cultural property protection, children and armed conflict, and conflict-related sexual violence. The emphasis on these topics is no surprise, as NATO’s 2022 Strategic Concept elevated human security as central to NATO’s approach on crisis prevention and management. That same year, the organization adopted the Human Security Approach and Guiding Principles. The emphasis on this topic in the latest SFA doctrine therefore reflects a broader recognition of the importance of human security for NATO’s operational legitimacy and effectiveness.
While the above-mentioned cross-cutting topics are certainly important, it remains unclear how NATO will balance these with local ownership and national norms that may possibly conflict with NATO values. In addition, whilst human security considerations are important from a Western perspective to achieve stability in the long-term, using such considerations as criteria for assistance might lead to a disadvantage in competition with other SFA providers such as Russia. According to Jack Watling and Nina Wilen, “the use of human rights violations is an important element of Russia’s approach to lock in partners.” NATO should not abandon its ideals, but it should be aware of these dynamics.
Conclusion: The Future of Security Force Assistance
The second edition of AJP 3-16 reflects NATO’s efforts to adapt Security Force Assistance to a rapidly evolving strategic environment. Lessons learned from Iraq, Afghanistan, and more recent crises in Europe and the Sahel have informed small changes in doctrine, emphasizing a broader definition of SFA, the importance of unity of effort in a competitive multi-actor environment, enhanced assessment tools, and the integration of human security and international law considerations. NATO increasingly recognizes that SFA must be culturally attuned and aligned with local structures to avoid creating dependency or undermining legitimacy.
At the same time, the doctrine demonstrates a careful balance between operational effectiveness and ethical imperatives. By codifying concepts such as Protection of Civilians, cultural awareness, and continuity of advisors, NATO seeks to ensure that its assistance strengthens host nation forces while respecting human rights and the norms of international law. Yet, challenges remain, particularly in managing local ownership and navigating competing SFA providers.
Ultimately, the updated doctrine represents both a strategic and moral evolution. It acknowledges past shortcomings while providing guidance for more resilient and effective Security Force Assistance. As NATO continues to operate across diverse theaters including the southern neighborhood, the lessons captured in this edition will be essential to ensuring that SFA contributes meaningfully to global stability and long-term security outcomes. Nevertheless, SFA remains a challenging endeavor that continues to require reevaluation from both academics and practitioners.
Vibeke Gootzen is a researcher in the Irregular Warfare and Special Operations team at the Netherlands Defence Academy. She holds a master degree in Conflict Studies (Utrecht University) and War & Psychiatry (King’s College London).
Main Image: U.S. Army advisors from Force Package 25-1, 54th Security Force Assistance Brigade, train alongside Albanian Armed Forces, Kosovo Security Force, and New Jersey National Guard soldiers during Exercise Immediate Response 25 in Albania, May 2025. Immediate Response is part of DEFENDER 25, U.S. Army Europe and Africa’s annual multinational exercise focused on NATO interoperability. (U.S. Army photo by Capt. Aaron Blevins).
The views expressed are those of the author(s) and do not reflect the official position of the Irregular Warfare Initiative, Princeton University’s Empirical Studies of Conflict Project, the Modern War Institute at West Point, or the United States Government.
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