Interview with Peter Maurer
Peter Maurer served as President of the International Committee of the Red Cross (ICRC) from 2012 to 2022. During his time as President, Maurer prioritized strengthening humanitarian diplomacy, engaging States and other actors for the respect of international humanitarian law, and improving the humanitarian response through innovation and new partnerships. Meanwhile, he oversaw an historic budget increase and organizational expansion. Prior to his role at the ICRC, Mr Maurer served as Secretary of State for Foreign Affairs in Switzerland and headed the Swiss Department of Foreign Affairs. Earlier, Mr Maurer held various positions representing Switzerland at the United Nations (UN) in New York, including Ambassador and Permanent Representative of Switzerland to the UN, Chairman of the UN's Fifth Committee, and member of the UN Peacebuilding Commission. Mr Maurer had first joined the Swiss diplomatic service in 1987, through which he held various positions in Bern, Pretoria and New York. Maurer was born in Thun, Switzerland in 1956. He studied history and international law in Bern, where he also earned a doctorate.
* This interview was conducted by Bruno Demeyere, Editor-in-Chief of the International Review of the Red Cross, and by Jillian Rafferty, Managing Editor of the International Review of the Red Cross, on 27 March 2022.
1. In the ten years of your mandate, what major geopolitical shifts have you observed, especially in the context of the features of armed conflict?
Although my mandate has lasted ten years, world history does not fit itself to the mandates of International Committee of the Red Cross (ICRC) presidents; rather, ICRC presidents are dropped into historical developments. With that in mind, I would like to enlarge the perspective beyond ten years and look at the trends as they have developed over the last three decades.
When the Cold War ended roughly thirty years ago, the world saw trends disrupted that had dominated international relations for decades. The post-Cold War period brought a surge of hope for a new multilateral order, which translated into some important consensus documents like the United Nations Agenda for Peace1 and Millennium Development Goals.2
Then, with the attacks of 11 September 2001 (9/11), the world saw another major shift, with counterterrorism becoming the predominant template of international relations under the lead role of the United States. Armed conflicts around the world were seen first and foremost in the context of fighting terrorism.
My own arrival at the ICRC ten years ago largely coincided with the tail end of the Arab Spring. Armed conflict was spreading through the region and beyond, becoming more deeply entrenched. Syria became the emblematic example of long-term, deep-impact protracted conflict, a pattern spreading into other contexts like Yemen and Iraq, and re-igniting the Palestinian issue. Inevitably, these evolving armed conflicts affected and shaped humanitarian work around the world.
Looking at the ten years of my presidency, I see a few distinct trends characterizing armed conflict: global and regional power competitions unresolved; fragmentation and proliferation of actors; marginalization and stigmatization of populations in the aftermath of wars; reconstruction slow or non-existent. Not confined to loss of life or injury, protracted conflicts are damaging entire social systems, essential services and economies. Vicious cycles of violence lead to protracted conflicts. We continue working in Iraq after forty years, in Yemen for more than sixty years, and in Afghanistan in excess of thirty years. These decades of war and instability shatter nations: from the immediate impact of the hostilities to the decay of infrastructure and social systems.
The hybridization of battlefields is a direct consequence of the digital transformation of warfare. Battlefields expanded from the ground, air and sea into cyberspace and outer space, and weapons were modernized and digitally enhanced, so becoming more precise. Hybridization is a humanitarian win and at the same time dramatically more lethal – a real source of humanitarian concern.
Hybrid battlefields became more unstructured and fragmented. War increasingly moved into cities and other populated areas with massively detrimental effects on people and systems. Wars were unfolding as multi-party armed conflicts, with multiple parties and combinations of local and international actors.
The unfortunate reality unfolding was that actors, weapons, battlefields and military strategies all pointed in the same direction: towards larger and more detrimental impacts of warfare on the civilian population.
The ICRC and most other humanitarian actors were challenged by these new realities: it had to update its understanding of the fundamental concepts that were underpinning international humanitarian law (IHL) and to ensure that they remained fit for purpose. Considering the massive impacts on civilians, key IHL concepts like distinction, proportionality and precaution needed to be sharpened and better understood. How could we interpret IHL in a way so that it could unfold its protective force in modern warfare?
Similar questions needed to be considered in the context of the digital transformation. We needed to develop a coherent understanding of core IHL concepts in the digital space. How do we apply IHL to a new and emerging class of weapons? How do we define an “attack” in the digital space? ICRC needed to step up its efforts to interpret and to help parties to armed conflict in their obligation to respect IHL. With new realities unfolding, we needed to question a long-held assumption that existing law was sufficient to address new challenges.
While most of the time, indeed, the law would offer guidance, better and sharper interpretative guidance was necessary, and work needed to be more systematically undertaken to identify true gaps in IHL's normative system.
2. What have these changes meant for the ICRC's work as a humanitarian organization and for the humanitarian sector more broadly? What opportunities do you see for the ICRC and its work – and what still worries you?
The ICRC's work breaks down into three pillars: law, operations and policy–diplomacy. For each of these pillars, the transformations of recent years have brought different implications.
With regard to the law, we had to assess the issues that needed renewed clarification or commentaries and those that eventually needed more comprehensive overhauls and calls for international negotiations.
With regard to operational activities, we had to rapidly adapt to increasing and transforming humanitarian needs, which put pressure on the organization to develop our own response regarding protection and assistance and to adapt to a landscape of needs. Mental health, sexual violence and connectivity emerged as important demands from affected populations.
With conflict agendas more prominently occupying political agendas, our upstream policy and diplomacy efforts needed to be enlarged and deepened. Conflict realities needed to be framed and reframed in the light of operational experiences and of our reading of the law. Accordingly, the priority policy issues shifted over the decade. The protection of hospitals and medical installations, the special needs of particularly vulnerable groups like families of missing people, victims of sexual violence or trauma-affected civilians, and the use of weapons in densely populated areas all became, more than ever before, priority areas of attention.
Over the course of my tenure as President, more issues found their way from field experience into international decision-making. I remember attending my first seminar of the Assembly of the ICRC in 2012 focusing on other situations of violence (OSVs) – or violence leading to humanitarian needs but not rising to the level of armed conflict. OSVs were traumatizing communities and were an area where ICRC could add value through applying its expertise in speaking and negotiating with arms bearers. Over the years this issue was joined by many other “new” issues where the ICRC previously had had limited engagement, including sexual violence, the climate crisis, mental health and civil–military dialogue. On my final trip as President to New York, the briefing file comprised twenty-five issues being discussed in multilateral fora.
Ultimately, pressure from conflict zones and affected populations have pushed the ICRC to continuously define its positions, concretize its legal reading and to launch a series of diplomatic initiatives bringing realities of armed conflict to political decision-making and public consciousness. In the course of such discussions, States and groups of States have championed such issues of concern and placed them on a more permanent basis on the international agenda.
While the ICRC continued to privilege bilateral and confidential dialogue with belligerents, we also articulated more often and more systematically recurring patterns of violations in more public space to bring them to the attention of high contracting parties collectively. The use of weapons, the protection of civilians, the conduct of hostilities, and the many sub-issues within each of these big themes and workstreams have sharpened our own thinking and ability to meet humanitarian needs.
What opportunities do I see? There are quite many. Firstly, with the ICRC's unique mix of legal mandate, operational experience, and capacity to interact with parties to conflict, evidence-based policy-making is an important objective. Similar to our founding fathers, we had to become advocates with States, experts of law and experienced translators from battlefield realities.
It is gratifying when that opportunity and promise play out. For instance, by collecting evidence from the field, we brought attacks on healthcare onto the multilateral agenda and built momentum in the international community to address those attacks.3 The attacks themselves had terrible humanitarian consequences, and the ICRC was able to use its unique role as an opportunity to bring consensus forward and influence real changes. While even broad consensus would not stop such attacks, consensus over their illegality was an important milestone.
Another example comes from recent efforts to regulate or constrain the conduct of hostilities in populated areas. As an institution, the ICRC brought to those discussions experience on the urbanization of armed conflict and the detrimental effects of urban warfare – and especially of using explosive weapons in such contexts.4 This allowed the ICRC to play a leading role in the redefinition of the use of explosive weapons in densely populated areas and to help steer international consensus towards a political declaration in this regard.
I also point to the digital transformation of warfare. While in kinetic warfare we focus on the respect for existing law, the digital world needed more careful thinking of extended interpretation and identification of legal gaps. In that context, I particularly welcomed the ICRC Legal Division's suggestion to convene a Global Advisory Board on digital threats and challenges. It became obvious that there was more work to be done in considering the future of warfare and its legal impact. In my own view, I do not expect a future of war that exclusively takes place in cyberspace or outer space – at least not as a stand-alone form of armed conflict. However, I do anticipate a hybridization of warfare, in which kinetic, digital and cyber- and space-based warfare will interact with each other as overlapping layers of armed conflict. This will pose new challenges for the ICRC's mandate as guardian and promoter of IHL.
Typically, lawyers look for clear and precise answers to important questions – and look to the law for unambiguous guidance. Lawyers’ work is often to bring clarity to a situation, in being able to clearly know and explain what is legal and illegal. In legal terms, hybrid warfare is challenging to conceptualize. Having multi-stakeholder expertise to navigate some of the challenging issues and to think creatively about future norms and laws seemed to me to be particularly important.
Finally, another challenge that the ICRC faces pertains to the increase in mis- and disinformation in today's world, which has made problematic the sheer establishment of what constitutes “the truth”. As a first step, we must accept that mis- and disinformation are part of our reality, both in- and outside of war. These phenomena have permeated all aspects of society.
However, accepting the existence of mis- and disinformation by no means implies that we should not address the problem. While we need, as an organization, to find ways to protect ourselves from misinformation, we need at the same time to think about norms and principles to frame the phenomenon.
Mis- and disinformation are especially important because of the way the ICRC works. So much of our work goes together with a need to have a clear and reliable evidence base, and to draw from our own experience in developing that evidence base. The need for such evidence is reflected throughout our institutional strategies, and the ICRC has put measures in place to ensure that the work we do is firmly based in evidence. However, mis- and disinformation attack the very evidence, no matter how well established it is. Part of managing that involves building the appropriate shields to protect against mis- and disinformation campaigns and to ensure that we can bring our evidence to bear on the discussions.
3. In your view, what were the ICRC's main institutional priorities when you started your mandate in 2012? How does that list compare to your list of priorities today, as your time as President comes to a close?
Looking at contexts, my primary concern relates to the longevity of crises, which has more than ever emerged as a key concern over the last decade – as observed in Afghanistan, Iraq, Yemen, the Horn of Africa and the Democratic Republic of Congo. The loops and re-loops of these crises have kept these contexts as top institutional priorities, while others, like Syria or the Sahel, were added to that list.
In terms of recurring themes, the list of priorities has been expanding. Most of the items on the list relate back to recurring patterns of disrespect of IHL, the protection of civilians first and foremost. After all, civilian victims represent the largest category of victims in most conflicts since the Second World War.
With a rapidly growing list of issues, the word “priorities” feels somewhat misplaced. It is obvious that patterns of disrespect and neglect over many issues represent an interrelated cluster of concern deserving attention of the ICRC and of the international community more broadly. What strikes me most is the attitude of transactionalism that is so common to belligerents – offering respect only in cases where the adversary is respecting the law, and of exceptionalism – legitimizing violations as measures in response to the exceptional cruelty of the adversary. In more than one context, the balance between military “necessity” and protection concerns has heavily tilted towards military logics, and norms have been implicitly downgraded to mere discretional guidance.
Finally, with the longevity of crisis and an increasingly deep and systemic impact, sustainable funding of humanitarian work has been an increasing concern. Not only will we need to focus on shrinking the needs and improving behaviour but also to expand financial support beyond State contributions. The ICRC therefore has worked to tap into new sources of finance – development funds, climate adaptation funds, private investments and all kinds of blended financial instruments.
In this context I also should highlight the importance of building bridges to other societal agendas, aspirations and constituencies: humanitarian work as much as it has to be rooted in neutral and impartial action needs also to be connected to efforts for peace, human rights development and climate change. Such efforts have been wrongly misunderstood by some as efforts to transform the ICRC into a development, climate change or peace organization. This could not be further from the truth: such efforts are rather a recognition that “humanitarian action” can never be an objective in itself, but rather a method hopefully leading to, and contribution to a broader aspiration.
Anchoring humanitarian work in broader aspirations is critical and part of the genius of our founding fathers, who aspired to create peaceful societies. While remaining principled in our work, we also need to move and work pragmatically with those who have broader objectives. In times of scarce resources, expanding agendas and multiple overlaps of efforts, building on our role as neutral intermediary is at the same time a step to building conditions for more sustainable peace.
Humanitarianism cannot be treated as a stand-alone effort. We must better connect ourselves to other ambitions in society, while always keeping our own key priorities in mind. As mentioned, this is not a new concept but rather the revitalization of the original purpose of the very creation of the Red Cross. The founding fathers did not see humanitarianism as a stand-alone objective, but rather as a contribution to peace. I have tried to carry their legacy forward during my presidency.
4. This edition of the International Review of the Red Cross explores how IHL has developed in the past, and how it may continue to develop in the future. What, in your view, does the future development of IHL hold? How can we move this agenda forward in an innovative way?
The future will start from where we are and what we do, including maintaining the well-established efforts on training, advocacy and compliance, the continuation of our confidential dialogue with belligerents, as well as broader national and international accountability efforts.
Moreover, leveraging behavioural science in IHL compliance efforts will certainly become more important as we have seen recently when looking at what drives actors to respect or disrespect the law.
Also, focus on violations will have to be complemented by looking at positive examples of compliance. Collecting such examples and transforming them into lessons learned for militaries and armed actors more generally will become more important, with the negative news re-enforced by prevalent media dynamics.
5. We often talk about the Fundamental Principles of the humanitarian movement. How have those Principles guided you in your leadership of the ICRC? What are your thoughts on the Principles and their practical application?
The Fundamental Principles are exactly what their name suggests: principles. As such, they are here to guide us in our own actions, not to be implemented or applied as such. Very often, we discuss principles as if they were norms or rules, which is not quite accurate. Principles are not, in fact, norms. Norms dictate action. They tell us, in concrete terms, what to do. Principles, by contrast, provide guidance for action. They inform and help steer our choices and behaviour.
Principles are particularly important, because of the complexity of situations we are navigating. The Fundamental Principles therefore help the organization decide how to position itself and how to guide its action.
Over the past the Fundamental Principles were an uncontested part of my work. I never had a doubt on the relevance of the Principles, given the realities in which we found ourselves. Respecting the Principles has meant trying to let them guide us. Whenever I came across difficult decisions or thorny situations, I turned to the Principles – and I found them immensely helpful in thinking challenges through. In doing so, it has been important to recognize that the Principles are not reality but are guiding our action in a difficult and complex environment. The Principles do their part by helping us cope with that complexity.
I remember a particular situation early on during the conflict in Syria. I was told that, because of the principle of impartiality, we should not run a medical programme in the government-controlled part of Syria, as long as we could not run a parallel or equivalent medical programme in territory run by armed groups. To me, framing impartiality this way missed the point. Of course, we needed to deploy considerable efforts to establish parallel programmes on both sides of the conflict, which we did. But failing to save lives anywhere simply because you cannot save equivalent lives everywhere was an important lesson from applying the Fundamental Principle of impartiality.
6. Humanitarian activities are understandably subject to public scrutiny, with various constituencies – donors, media, affected communities, the public at large – having high expectations of humanitarian organizations. At the same time, our world is rife with mis- and disinformation. How can and does the ICRC navigate communicating its own work, and doing that work well in that environment?
There is no easy answer to this question. As we are encountering in the social media space, the interface of confidentiality and public communication is evolving with the challenges.
While we can certainly enhance our presence in social media by evidence-based communication and strengthen our protective shields against mis- and disinformation, it is important to think creatively about more adapted communication formats. Building trust with the public and the communities we serve will remain critical. The reality is that many people do not fall for the misinformation's traps. Though mis- and disinformation can make the world – and even the truth – feel quite murky, the public is critical and more resilient than one may think at first sight. With that resilience and clarity in mind, the ICRC must remember a key fact: our own work is our greatest tool in countering misinformation and in communicating our work and values. When we can demonstrate credible action that contradicts mis- and disinformation, and when the public experiences our work as countering that mis- and disinformation, we make headway.
Finally, we must remember that, while the modalities of misinformation have changed, this is neither a new nor a uniquely modern story. It has long been said that in war, the first victim is truth. Mis- and disinformation are a continuation in the digital world of the displacement of the truth.
Experience shows us that good action which brings us close to communities, combined with diplomatic and policy explanations of our work, bring us a long way in countering mis- and disinformation.
7. The ICRC's mandate identifies the organization's core priority as “ensuring humanitarian protection and assistance for victims of armed conflict and other situations of violence”. What trends have you observed in the ICRC's ability to deliver on protection, on one hand, and assistance, on the other?
While protection and assistance may represent different methods of humanitarian action, they go together. Focusing our efforts on the interaction of both approaches is critical as it is unsustainable to deliver humanitarian assistance without trying to shrink the need for that assistance and without trying to change the behaviours that created those needs to begin with.
Failing to link protection and assistance risks undermining the humanitarian sector overall. There is a real danger that the humanitarian sector could lose the positive attitude and goodwill of better-resourced societies if we are seen just throwing assistance at problems. We must demonstrate to our donors that their financial resources are used to help those in need – and central to that justification is that we are working actively with relevant parties to better comply with IHL's core principles and reduce the needs at the outset. When we can maintain a reasonable balance and linkage between the two approaches, we go a long way in maintaining goodwill toward both protection and assistance.
Another problem needs to be mentioned in that context: experience tells us that protection and assistance are linked on the ground. In the real world, calls for assistance never dominate calls for protection. Rather, affected populations are deeply concerned with both: they want to eat and to drink clean water, and they are at the same time concerned with the whereabouts of their loved ones. They are as much concerned with lack of inclusion and discrimination in their daily lives as they are with mere survival. Having one without the other, or one at the expense of the other, would simply be an inadequate humanitarian response. People have some needs that can be met via assistance work, and others that can only be responded to via engagement, dialogue and behaviour change.
8. We often hear that civic and humanitarian space is shrinking, which often takes the form of hesitation to welcome humanitarian actors and their work. Practically, how do you overcome this resistance?
For the ICRC, the protection of humanitarian space is largely in the hands of one key branch of the organization's work: frontline negotiation. It is through this work that we can protect and enlarge humanitarian space. To be sure, other elements of our work contribute to that protection, too. Diplomacy, for example, can help confirm the importance of protecting humanitarian space in multilateral fora. Still, at the end of the day, humanitarian space is the result of practical arrangements made between belligerents and humanitarian frontline negotiators.
As an organization, it is critical that we are at the forefront of this effort to protect humanitarian space. Our work cannot exist without a robust – and robustly protected – humanitarian space, which in turn depends on practical arrangements, hammered out by skilled negotiators. As with all our work, we never sacrifice or negotiate on our core principles. Rather, we allow those principles to guide us toward the operating space to do our important work.
All of this relies on our “licence to operate”. The humanitarian space defines our ability to operate. We have a licence to operate when belligerents accept our work and priorities. And belligerents accept what we do, when we are able, at least in part, to consistently strike the right balance among our various priorities and respond to the convergent interests of belligerents themselves. Building this layered approach through negotiation is both a complex skill and a true art form.
Regarding frontline negotiations, the ICRC has two powerful traditions in our institutional genetics that drive this work. The first is our mandate as neutral intermediary, through which we carry out these negotiations. Being a recognized neutral intermediary is a powerful component of our institutional mandate. This gives us the legitimacy to make proposals on and negotiate for humanitarian spaces. In some ways, this is like how Article 99 of the United Nations Charter provides a mandate and operating parameters for the United Nations Secretary-General.
The second tradition is our awareness as an organization that frontline negotiation is a place of experience and of experimentation for negotiators, who themselves make up a community of practice and practitioners. In other words, frontline negotiations simply cannot be guided by the institutional centre alone. Rather, they must be driven largely by the negotiators themselves – and the negotiators, as a professional community adept in addressing these issues, are exactly to whom we should be turning to.
Institutionally, we can support the development of negotiating skills and we can develop and complement frontline negotiators with policy and diplomatic work at multiple levels; however, in essence, the humanitarian space is created at the frontline, and by the frontline negotiations, and not through resolutions in faraway international fora.
9. Looking back on your time as President, what achievements are you most proud of? And may we ask – what leaves you disappointed? What advice would you give to your successor?
Regarding our policy work, success means that we can get across to those in positions of power during crises and convince them to prioritize a humanitarian perspective. Overcoming blockages to access and moving away from unhelpful behaviour are small successes when diplomatic conversations lead to meaningful behaviour change.
In legal work, a breakthrough toward broader consensus in an international negotiation, and changing internal laws and regulations to make them compatible with IHL are moments of satisfaction. Just this year (2022), we saw the conclusion of a political declaration on the use of explosive weapons in populated areas. Achieving a strong declaration after a decade of work and incremental progress is a success story in legal terms.
Operationally, success stories are reflected in impact on the ground. It can be incredibly tangible – and incredibly moving – to experience and be part of operational advances. For example, seeing a family reunification is a major and positive emotional moment – most of all for the family involved, of course, but also for humanitarian workers who strive to make these moments a reality. Bringing fresh water into a situation of dire need is, likewise, a positive moment. Every day, the ICRC is so privileged to produce these positive experiences that have a real and direct impact on people's lives – and we should be proud of that.
On a more frustrating side, I would focus on just one thing. As the organization has grown and continues to grow, we will face inevitable tensions between managing an increasingly large organization, on one hand, and understandable resistance to having our humanitarian work bogged down by bureaucracy, on the other hand. As a large organization with financial and human resources, supply-chain demands, and a need for adept management, we need to embrace accountability structures and bureaucratic organizational controls. These will prove increasingly central in maintaining old and attracting new donor support, as well. However, at the same time, these accountability structures and bureaucratic procedures can overshadow and overburden our colleagues, who want the needs on the ground to drive their work – rather than to be responding to management and bureaucratic needs. This can create understandable frustration and tension. Finding the right balance among these priorities is delicate and requires careful, fair-minded thinking.
In other words: we cannot manage an organization as big and productive as the ICRC without processes, controls and back-ups. At the same time, almost no one comes to work with the ICRC to manage processes, but rather to engage in vital humanitarian work. Balancing is the challenge moving forward.
10. As you hand over leadership of the organization 160 years after Henri Dunant's A Memory of Solferino5 was published, how does the current moment form part of the ICRC's long trajectory? Where does the organization go in the coming decade?
During this conversation, we have talked about risks and opportunities. The risks are many-fold. Every humanitarian and everyone in international and multilateral institutions has, at least to some degree, a gloomy picture of today's risk landscape. I cannot imagine that we are about to see an easy exit from the basic modern trend of complex emergencies, massive fragilities, social tensions, violent conflict and humanitarian needs induced by these complexities. We will continue to see these developments in real time.
Despite those risks, we do have serious opportunities, hooks and entry points. We have discussed these opportunities – innovative approaches and technologies enhancing delivery and financing humanitarian action, enhancing negotiating skills for frontliners and many more. The big question for the future is whether the organization does sufficiently well in leveraging opportunities and trying to minimize risk.
I believe that we have made much progress in thinking creatively about the future, in preparing the ground for innovative practices and for efficient and effective humanitarianism.
My sense is, despite all the challenges, we have all the ingredients to remain a responder to these challenges. That is what counts. We cannot foresee the future, but we can be prepared to manage it well.
- 1An Agenda for Peace: Preventive Diplomacy, Peacemaking and Peace-Keeping: Report of the Secretary-General pursuant to the statement adopted by the Summit Meeting of the Security Council on 3 January 992, UN Doc. A/47/277, 7 June 992.
- 2See United Nations, Millennium Development Goals, available at: www.un.org/millenniumgoals/ (all internet references were accessed in October 0).
- 3See ICRC, “New Global System to Monitor Attacks on Health Care”, 28 May 2018, available at: www.icrc.org/en/document/new-global-system-monitor-attacks-health-care; ICRC, “Health-Care Providers, Patients Suffer Thousands Of Attacks on Health-Care Services over the Past Five Years, ICRC Data Show”, May 2021, available at: www.icrc.org/en/document/health-care-providers-patients-suffer-thousand….
- 4See ICRC, International Humanitarian Law and the Challenges of Contemporary Armed Conflicts Recommitting to Protection in Armed Conflict on the 70th Anniversary of the Geneva Conventions, Geneva, 2019, available at: www.icrc.org/en/document/icrc-report-ihl-and-challenges-contemporary-ar… report. See “Interview with Eirini Giorgou”, International Review of the Red Cross, Vol. 10, No. 2–3, 2022.
- 5Henri Dunant, A Memory of Solferino, Impremerie Jules-Guillaume Fick, Geneva, 1862, available at: www.icrc.org/en/doc/assets/files/publications/icrc-002-0361.pdf.