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Remote-Controlled Aerial Vehicles – Made-to-Measure Effectiveness for Better Protection of our Soldiers on Missions

Today, according to analysts, nearly ninety countries use remote-controlled aerial vehicles for military purposes. One-third of these countries have the capability to fly armed missions. Hence armed remote-controlled aerial vehicles are not something completely new – they are now a widespread reality. And the trend is continuing, because many countries – including in Europe – find that these aircraft have obvious advantages. The question of the position Germany should take with regard to this situation is not only a military one. It also has a bearing on security policy and industrial policy, and is often closely linked to ethical and moral issues. Thus the decision regarding the development and procurement of remote-controlled aerial vehicles should be taken not only according to costs and benefits, but rather only after careful consideration of their legality and legitimacy. To take all of this into account, in their coalition agreement the governing parties promised a review of the associated issues with regard to international law, constitutional law, security policy and ethics, before making any decision. Such a comprehensive review seems politically expedient in view of the ongoing debate – at least in sections of German society – about armed remote-controlled aerial vehicles. After all, in this important question for the future, the German federal government and federal parliament (Bundestag) need not only to find the objectively correct answer for the German armed forces (Bundeswehr) and for Germany as a high-tech location, but also to advocate and explain this decision to society. There are good reasons for addressing this issue as promptly as possible. Firstly, other countries are rapidly gaining a technological advantage. Secondly, the Bundeswehr’s use of unarmed remote-controlled aircraft in Afghanistan for reconnaissance and surveillance made two things very clear: A) The much clearer situational overview that they provided substantially reduced the risk for our soldiers during operations, and hence significantly increased their safety and that of the innocent civilian population. B) The fact that they were not armed represents a serious deficiency, since close air support when needed can only be provided with a time delay and reduced precision. Our allies in France, Great Britain, Italy and the Netherlands had the same experience and have already taken appropriate decisions to arm their forces. Comparable decisions are imminent in Poland and Spain. In none of these countries has there been or is there currently a similar, at times emotionally charged debate in respect of ethical and moral issues and possible negative consequences resulting from this technology. Germany, on the other hand, is faced with losing experience and expertise already gained in the operation and use of remote-controlled aircraft, since the unmanned aerial vehicles leased for the Bundeswehr from Israel can only be deployed in Afghanistan, while the ISAF mission there is coming to an end and technological development is stagnating for want of further orders. For well over two years, therefore, the German Air Force has been pointing to existing and emerging capability shortfalls and arguing for the procurement of armed remote-controlled aerial vehicles in political, church, peace ethics and other social forums. Now there are signs that the Bundestag will turn its attention to this issue in the early summer – or more precisely there will be an expert hearing in the Defense Committee of the German Bundestag. It therefore seems a suitable time to give a brief summary of the issues as they currently stand, as a constructive contribution to political decision-making from a military perspective.

Regrettably, the debate in Germany about armed remote-controlled aerial vehicles is strongly colored by the legally and ethically problematic use by other countries – known as “targeted killing” – which, however, is the subject of heated debate in these countries as well. Yet the Bundeswehr is solely concerned with having a military capability so that the mission objectives which are issued by the German Bundestag and based on our social values and constitutional standards can be implemented as effectively as possible and with the lowest reasonable risk to our soldiers and to the innocent civilian population. The strong parliamentary control mechanisms which exist in our democratic constitutional state, which are enshrined in the German Parliamentary Participation Act (Parlamentsbeteiligungsgesetz, ParlBG), and the responsible practice of the executive, which generally bases operational mandates on a broad parliamentary majority, have proven highly successful in past years in all armed deployments of the Bundeswehr. They reliably ensure that remote-controlled aerial vehicles can only be used legally and legitimately, as is the case for all other weapons systems.
I see no objectively justifiable reason to doubt this. Therefore, the debate being conducted in Germany can be clearly separated from the deployment practices of other states. In my view, it can essentially focus on four main questions:


  1. Is there a military need, beyond the use of remote-controlled aerial vehicles for reconnaissance, to have the option of arming such aircraft for military operations?
  2. Is the use of armed remote-controlled aerial vehicles permitted under international and constitutional law?
  3. Beyond the issue of legality, is it possible to find a satisfactory answer to the question of the legitimacy of such weapons?
  4. In the development of remote-controlled aerial vehicles, are there technological trends which it would be necessary to take preventive action against via arms control policy initiatives?


Is there a military need, beyond the use of remote-controlled aerial vehicles for reconnaissance, to have the option of arming such aircraft for military operations?

It is highly likely that current and future crises and conflicts will be characterized by asymmetric warfare. In general, an enemy will seek to avoid our strengths and attack our weaknesses. It is not only in Afghanistan that we are seeing this pattern; it was also evident in other conflicts – in Libya and Mali – under somewhat different circumstances. The conflict in Ukraine, with its unconventional methods of applying military force via local militia and covert special forces operations, can also be construed as an asymmetric strategy. Such forms of warfare, in which an asymmetric alignment is already part of the strategic approach, make it difficult to uphold and indeed in some respects deliberately undermine the principles of discrimination and proportionality under international humanitarian law. To satisfy these requirements in spite of such difficulty, it is necessary at the strategic, operational and above all tactical level – in the first instance regardless of the methods used – to obtain the right information at the right time in order to be able to take decisions and act at all. If this information is missing, then under increasing pressure to act – which is sometimes not possible to influence – as the situation develops, the result can be that decisions are taken which, although subjectively correct, subsequently and objectively turn out to be wrong or disproportionate. The airstrike on two tanker trucks in Kunduz in 2009 could serve as a case in point. Even if an enemy very deliberately uses their own lack of identifiability as a weapon – for example by blending in with the civilian population – it is first of all necessary, as a very general principle, to be able to monitor areas continuously and in their entirety. This is the only way to detect patterns of movement and behavior which enable conclusions as to the adversary’s identity and intentions. Continuous reconnaissance and surveillance is often only possible from the air, yet this is not feasible using manned aircraft or satellites. These can only take snapshots and reconnoiter stationary objects or infrastructure, but not moving objects or behavioral patterns of a covertly fighting enemy. And the more distant and remote a conflict area is, the more difficult it becomes to obtain the necessary situational overview by other means, including on-the-ground reconnaissance and surveillance. Remote-controlled aircraft, however, can do all of this. Firstly, they can stay in the air for longer than the human endurance limit. Because they never get tired, they are essentially always there, including for example to permanently accompany a patrol over an extended period of time. Modern remote-controlled aerial vehicles can now stay in the air for up to forty hours at a time, enabling them to remain in the theater of operations for long enough, even if they have to fly a long way to get there. Secondly, remote-controlled aircraft are extraordinarily flexible. Since they are constantly present in the theater of operations, they can change their reconnaissance objectives within minutes, according to priorities, and then continue their surveillance for a further long period. Thirdly, they are discreet and inconspicuous. This is particularly important when it comes to distinguishing a covertly fighting adversary from the innocent civilian population. If it was possible to hear or see the reconnaissance aircraft, the enemy would know they were being watched and change their behavior accordingly. Then it would hardly be possible to distinguish the enemy anymore. The German Air Force has successfully used the remote-controlled aircraft HERON 1 in Afghanistan for surveillance and reconnaissance. Hardly a patrol leaves camp today without information from a HERON being involved in the preparation and without being accompanied by a HERON. The presence of the remote-controlled aircraft has considerably increased the safety of our soldiers during missions. Unfortunately, however, reconnaissance systems can only observe enemy combatants during an attack on our soldiers. They cannot intervene effectively and help. During a visit to Afghanistan, I witnessed a German patrol fall into an ambush, despite good preparation. As a result of the better situational overview which HERON helped provide, the patrol was able to successfully defend itself. The insurgents gave up their attack after a short engagement, took their weapons to a hiding place, and disappeared again. Had the attackers been better prepared, however, and acted more aggressively and resolutely, successful defense would not have been possible without armed aerial support. Yet the HERON that was already on the scene and would have had to help in that situation, would not have been armed. It would have been necessary first to call in one of our allies’ warplanes. Valuable time would have been lost, in which our soldiers would have been exposed to grave danger in the battle on the ground. And once the warplane arrived, the pilot would have first needed to be briefed on the situation, from the ground, and identify his target. This would have been a possible additional source of error, since it would not have been possible to rule out mix-ups with our own forces or innocent civilians in the stress of battle that would then prevail. In contrast, an armed remote-controlled aerial vehicle would have been able to intervene and help immediately, without any extra coordination effort, and on the basis of a situational overview which already existed, precisely, proportionately and without the risk of mix-ups. In calling for armed remote-controlled aerial vehicles, I am primarily concerned with countering an attack on our soldiers in an armed conflict as effectively as possible – but only just as effectively as necessary – and thus fulfilling the politically assigned mandate while keeping to the rules of engagement and maintaining a sense of proportion. With regard to the military necessity, therefore, my summary is as clear as it is simple: Armed remote-controlled aerial vehicles are necessary tactically and operationally just as much as it is a duty of care toward soldiers during deployment to arm remote-controlled aerial vehicles in case of need.

Is the use of armed remote-controlled aerial vehicles permitted under international and constitutional law?

From the point of view of the German Air Force, the deployment of armed remote-controlled aerial vehicles within the framework determined for the Bundeswehr by international law and the German constitution is not merely conceivable, rather it is subject to the same requirements, restrictions and regulations as the deployment of the Bundeswehr as a whole. Exaggerating somewhat, one might say that it is only possible within precisely this framework! With regard to the constitutional framework, one can note that for the first time in German history, it is our people – our society – who decide to deploy the Bundeswehr, after careful consideration, through their representatives’ mandate in the German parliament, the Bundestag. The German Bundestag also decides on the type of military force exerted in the context of such deployments. It sets out mandatory boundaries and conditions for the use of weapons by German soldiers, taking international law into account in the rules of engagement. Thus deployments in general, and hence also deployments of armed remote-controlled aerial vehicles, not only follow the mandatory requirements and rules of engagement applicable to deployment in general, they are also – as are all deployments – subject to supervision by the relevant constitutional bodies. The parliamentary groups in the Bundestag can demand comprehensive information, and the parliamentary groups and members of the German parliament use this right extensively. From the quality of meals to strategic questions regarding the Afghanistan mission itself, just about every aspect concerning the Bundeswehr has been and is the object of inquiry. With the parliamentary commissioner for the armed forces, the Bundestag has a further supporting body, which at the same time is also highly committed to bringing forward the concerns of soldiers. The Defense Committee, which in any case is constantly active, can additionally act as an investigation committee – which it did twice in the last legislative period alone. The Budget Committee checks on amounts and equipment – and in the past, for example, it allocated resources for the procurement of different items than the Bundeswehr applied for. Both citizenry and soldiers can trust in these institutions. In my opinion, the idea – which is apparently expressed as a result of the pattern of problematic deployment practice by other countries – that by introducing remote-controlled armed aerial vehicles the Bundeswehr or German Air Force is on the path toward illegal killings, completely – indeed almost criminally – ignores our social, our political, and our legal framework. What about international law issues? Unlike chemical weapons or cluster munitions, which are banned because they cannot meet various humanitarian criteria of international law, there is no general prohibition under international law with regard to manufacturing, buying or using remote-controlled aerial vehicles. Since remote-controlled aircraft are not essentially different than manned warplanes, it can be assumed that initiatives to ban them will have no prospect of success. But of course the armed deployment of remote-controlled aerial vehicles – as for all other weapons – must take place within the precepts of international law. Among other things, these forbid the disproportionate and indiscriminate use of military force. In Germany, even the suspicion of a violation will result in investigations by the public prosecutor. Up to the present day, no investigatory proceedings in connection with the use of weapons in missions have ever resulted in charges being brought against a soldier. This makes it clear that our soldiers are professionally aware of what the use of military force can mean, and above all what limits are imposed on them in each case for its specific deployment. Moreover, the protection of innocent civilians is a maxim of international law which is upheld in every deployment of weapons authorized by the Bundestag. The higher the precision, the better the targeting, and the greater the scalability with which force can be exerted, the better the armed forces can satisfy this imperative. Hence, as a result of their inherent characteristics, combined with rules of engagement that are consistent with international and national law, remote-controlled armed aerial vehicles afford greater protection to innocent civilians in an armed conflict. Hence one can say with some justification, even if it is something of an exaggeration, that precisely on account of the protection of innocent civilians and the need to guarantee, as comprehensively as possible, discrimination and also the proportionality of means, there is really no way to avoid using armed remote-controlled aerial vehicles.

Beyond the issue of legality, is it possible to find a satisfactory answer to the question of the legitimacy of such weapons?

With regard to ethical and moral issues, it is often argued that the use of remote-controlled armed aerial vehicles will reduce the inhibition threshold for killing. Death is abstracted, it is said, and distance killing is unnecessarily cruel. In my view, owing to the primacy of politics, concerns that the threshold for the use of force could fall are unfounded. Deployments of military force take place after a full consideration of all relevant factors. Because of the potentially serious consequences, such decisions are never taken lightly and always as a last resort. Furthermore, particularly with regard to armed remote-controlled aerial vehicles, I cannot see that these would lead to an erosion of the deterrent military strategy elements and hence contribute to a falling inhibition threshold. Rather, a weapon which can be deployed rapidly, precisely and scalably is a useful addition to the currently available spectrum of military options and therefore strengthens precisely the preventive elements of the overall strategy. The desire to put distance between one’s own soldiers and the enemy yet still fight effectively is not new. Ever since the invention of the bow and arrow, attempts have been made to protect one’s own soldiers from the effects of the enemy’s weapons. This was and is an understandable and legitimate endeavor, which has certainly shaped and will continue to shape warfare. However, I would not be able to find any added moral value in deliberately withholding a technological advantage from one’s own soldiers, who risk their lives around the world for the freedom, values and rights of our citizens and other people, merely in order to force a supposed “chivalrousness” on the battlefield. Such ideas, which come along in ethical guise, suggest a basic attitude more suited to a sporting competition, along with the demand that a military operation should also be based on such an attitude. In view of the serious consequences of fighting – wounding and death – this seems to me to be inappropriate as a general ethical requirement, and in any case unrealistic with regard to the enemy. Soldiers accept risks in order to protect themselves, their fellow soldiers, or innocent civilians, and to fulfill the mission authorized by the Bundestag. Meanwhile they always remain citizens of our country. For this reason alone, their own rights, for example to physical integrity, should not be diminished more than is necessary. They do not need to accept a greater risk in order to protect the enemy. I consider that making such demands of our soldiers is utterly immoral and extremely cynical. By contrast, I consider it morally imperative to call for our soldiers to have the best possible equipment – indeed, the best that our highly developed society can legally and financially provide. The principle should be that one’s own soldiers are exposed to the least possible risk and given the best possible support and protection during their dangerous mission. It also remains unclear to me why the arming of remote-controlled aerial vehicles in particular should create a new ethical dimension or category of weapons. Armed remote-controlled aircraft are not different than manned warplanes, except for the fact that the pilot sits not in the aircraft itself but in the control segment on the ground. In both cases, it is humans who act and in both cases this action is subject to identical legal and moral standards and rules.

In the case of armed remote-controlled aircraft, the aspect of human decision-making is even more pronounced than in manned warplanes, since here it is not a single pilot in the cockpit making a decision within a few seconds but rather a team of two to three operators who decide jointly, and after careful consideration. Hence the use of remote-controlled aerial vehicles is not ethically subject to any different principle than the use of military force in general. Objectively, the specified rules of engagement can be adhered to even more reliably.

In the development of remote-controlled aerial vehicles, are there technological trends which it would be necessary to take preventive action against via arms control policy initiatives?

Critics of armed remote-controlled aerial vehicles fear that their development and procurement mark the beginnings of the development of automated weapons systems which, at some time in the future, could autonomously wage wars without human intervention. Hence they oppose their development and procurement from the outset as being the “start of a slippery slope”. I do share this concern, but only with a view to the distant future, if it ever came to gradually replacing manned warplanes with a future generation of remote-controlled warplanes. In some combat situations, particularly in direct combat against other warplanes, owing to the associated pace of action it is often necessary to make instant decisions and take immediate action, which the pilot in the cockpit is ideally placed to do. This contrasts with the physical limits resulting from the time it takes sensor data and control signals to travel between remote-controlled warplanes and pilots on the ground, especially via satellites. In a number of countries, work is already underway on technological solutions which in the more distant future (2025+) will be able to process sensor data directly and allow the on-board software to decide on target selection and the use of weapons. I find this trend extremely problematic, since it shifts the legal and moral dimension of weapon deployment from soldiers and their ability to weigh this up directly in battle, to the far-away development departments of software providers. In war, when it comes to the ultimate decision over life and death, humans must always be able to make the final decision directly. They must not let this decision be taken by a piece of computer software, even if this were technically feasible. To thwart such a problematic development early on and with lasting effect, I advocate suitable arms control policy initiatives and the development of an international code of conduct aimed at stopping such activity. With the technology available today and in the foreseeable future, whose potential procurement is currently the subject of debate, this degree of automation is still not possible. At any rate in the remote-controlled aerial vehicles that are available over the next ten to fifteen years, the direct decision to use weapons will still be taken by soldiers, who are thoroughly trained to adhere to the politically approved rules of engagement, and who are familiar with the mandatory principles under international law regarding the use of military force, and take these into account in their decisions.

In summary, I would like to say that remote-controlled aerial vehicles are an especially effective and efficient means of obtaining important information, particularly in asymmetric conflicts. With a good, detailed situational overview serving as the basis for even better decisions, and weapons fire that is appropriate for the situation, rapid, easily available and scalable, the risk for deployed soldiers is minimized or reduced. Armed unmanned aerial vehicles considerably reduce the amount of time and coordination work required to help our own and allied forces. This is something that our duty to care and provide demands. Furthermore, they are practically imperative because of the reduced risk of harm, and for innocent civilians for reasons of proportionality and discrimination. From a moral point of view and with regard to international law, armed remote-controlled aircraft are not different than other, existing weapons systems. Ethical questions only become relevant when humans – whether soldiers or political decision-makers – use armed remote-controlled aerial vehicles. Since the use of armed remote-controlled aerial vehicles is tied to the same principles of international law, national law and ethics as the use of military force in general, in our democratic constitutional state there is no reason to fear misuse or to abandon these weapons from the outset because of such concerns. To conclude, let us turn to German public opinion, which speaks for itself. In April 2013, the Forsa institute conducted a representative survey on armed remote-controlled aerial vehicles. 27% of German people generally did not want such systems to be used. However, 59% could imagine their use under certain conditions, such as to prevent danger, and 12% generally supported their use.



Karl Müllner joined the Bundeswehr in 1976 as a Non-Commisioned Officer candidate. After admission to become an Officer, he was trained as a fighter pilot in 1981/82 and, from 1983 on, served as a fighter pilot, instructor pilot, weapons instructor and operations officer. In 1990 he became Squadron Commander in Fighter Wing 74 “Mölders”. After serving as a staff officer and completing General Staff training, from 1996, he was Group Commander in Fighter Wing  73 “Steinhoff” in Laage. From 1998, he was Assistant Branch Chief for military policy and bilateral relations in the German Federal Ministry of Defense. In 2000 he became Commodore of the Fighter Wing  74 “Mölders”. From 2002 he was Head of Division A3 in the German Air Force Command. 2003 he became Branch Chief Military Policy in the Ministry of Defense. In 2005, he was promoted to Deputy Assistant Chief of Staff Military Policy. From 2007 he was Commander of the 2nd Air Force Division in Birkenfeld, and, from 2009, Assistant Chief of Staff Military Policy in the German Federal Ministry of Defense. Müllner has been Chief of Staff of the German Air Force since 2012.