The author's investigation reveals how Germany uses South Africa--and other African countries--as its air borders to prevent some Africans, with valid Schengen visas, from travelling to Germany. The article uses the case of Zimbabwean congregants.
Tawanda Mulonga  and five of his fellow congregants from Northern Zimbabwe are wary of the journey ahead. They are busy preparing for their next visit to Germany. In August 2017, it would have been their turn to travel and celebrate the 20th anniversary of their partnership with the parish of the Evangelical Church of Oranienburg nearby Berlin. But they never made it beyond the boarding gate of their Lufthansa flight LH 573 from the O.R.Tambo International Airport of Johannesburg to Frankfurt.
While the group is waiting to be boarded, it is deemed suspicious by employees of Checkport South Africa:
"[They were] moving around like they were looking for something", Mr Mulonga remembers.
Moments later, a tall white man starts interrogating the group doubting their willingness to return to Zimbabwe once their trip is over. Mr Mulonga: "I asked him why should I run away from my home country? He did not like that question."
The tall white man goes and makes a phone call instead and eventually comes to the conclusion that the valid Schengen visas and complete set of necessary documents which the six travellers present him with do not make up for the small number of their bags and the status of formal unemployment of most of them. The group is however equipped with legalised letters of obligation submitted by their hosts officially vouching, under distraint, that they bear any costs related to their guests' visit, a possibility commonly provided for under the Schengen visa regulations.
The tall white man writes, "cancelled" onto the visa marks of all six passports and does not issue the group with anything in writing regarding the legal basis of what is happening.
After an unsuccessful odyssey for information at the airport, the thunderstruck group take the bus back to Zimbabwe. By then, their plane has long landed in Europe where their friends, too, find it hard to understand that their congregation's donation of close to 7.000 euros (R 110.000) for financing just the flights of their partners should have vanished into thin air.
An unspectacular variant of Europe's border in Africa
This is not an isolated case but usual business at O.R.Tambo International Airport. The author has gathered similar testimonials from South African, Namibian and Ivorian passport holders. There are strong indications that tens of thousands of African passengers in possession of valid European Union (EU) and United Kingdom visas are affected each year by this unspectacular variant of Europe's externalised border regime established at international African airports.
Statistical data are either not collected or not publicly available. But figures of an EU report on Europe's migration-related activities in Kenya suggest that 1.764 passengers were denied boarding at Nairobi's Jomo Kenyatta International Airport between January 2014 and November 2015 on the ground of mere suspicions raised against their travel intentions.
Even before the 11 September 2001 attacks intensified the global trend towards confining human mobility to risk management, an EU directive was adopted in June 2001 that provides for airlines to be charged between 3.000 and 500.000 euros by the national authorities of a Schengen country of destination for each "third-country" passenger deemed inadmissible by immigration police on arrival.
This and subsequent directives have effectively led to the privatisation of immigration control with airlines outsourcing the task of screening, before departure, both the validity of the travel documents and the trustworthiness of the travel intentions of their passengers, to private ground handling companies such as Checkport which belongs to the HNA Group-owned Swissport International Ltd..
Matching passports and questioning passengers at a boarding gate at O.R.Tambo International Airport, 2017. © O.Klimm
In the absence of clearly defined and transparent categories for assessing passengers' possible intentions to "overstay" or alter their purpose of visit, more often than not racist and essentially anti-poor patterns of suspicion trump facticity during the questionings at boarding gates. The devastating consequences the ensuing pull-outs can have for asylum seekers were highlighted by the British Refugee Council, amongst others, ten years ago already.
What the "offloads" (in airport jargon) mean for the fully documented travellers on the brighter side of the dehumanising continuum of mobility restrictions and identity fixations is mostly less dramatic but still painful, not least financially.
The all-encompassing vagueness of the airlines' clauses on refusal of carriage makes it difficult to claim any form of compensation and indicates that pull-outs are frequent incidents which the airlines are well-prepared for. Legally, the final decision whether or not to board a passenger rests with the airlines and, by extension, with their ground handling contractors. In most boarding gate pull-out cases this is where the story ends.
A rectangle of lawlessness
The reply  that Lufthansa sent on 14 February 2018 to the claims for damages by the German partners of Mr. Mulonga is, therefore, all the more astonishing:
"(... ) We are asking for your understanding that we are only liable for damages that have been caused by us or one of our contracted service providers. The reason for the refusal of carriage [of your guests] has however been a decision made by the German Federal Police ["Bundespolizei"]. (... )" (translated from German by the author).
The tall white man who prevented Mr. Mulonga and his group from leaving South Africa at the boarding gate is indeed a member of the German Federal Police and, like his colleagues, accredited as staff of the German embassy in Pretoria by the government of South Africa.
The presence of German police in South Africa dates back to at least 2004 when an EU Council regulation formalised a worldwide network of European immigration liaison officers (ILOs). Their mandate is to network with all public and private actors linked to migration in their host countries and to be "document advisors" to visa-issuing consular staff and to employees of the passenger handling industry. They are not to take any executive decisions, not to police.
Effectively, that is however precisely what they do. On a day-to-day basis, German police stand by and intervene at their sole discretion in the routine questionings of passengers queuing to be boarded on direct flights to Germany with Lufthansa, South African Airways etc.
A Checkport employee working at O.R.Tambo International Airport once put it like this: "ground handling staff do not do anything that runs counter to what an ILO says". Despite the standard liability disclaimers agreed on between ground handlers and carriers, the pressure on screening staff not to give rise to difficulties for their airline clients or to bring their own company into disrepute is very real. This is exemplified by a case of dismissal for negligence of Checkport employees heard by the Labour Appeal Court of South Africa in 2008.
At the time of publishing, Swissport and Checkport South Africa have not provided any substantial replies to the author's repeated enquiry about the nature of their cooperation with European ILOs and about how human discretion - and arbitrariness - on passengers' trustworthiness is entered into which information systems. If the facticity of their law-abiding mobility counts for nothing, are Africans at least protected from the profiling fictions their travelling data can be made to feed?
The consular section of the German embassy in Harare, who had issued the visas to the Zimbabwean congregants, on 20 June 2018 has refused to seal as "cancelled without prejudice" last year's incriminating visa mark scribbles in the group's passports - pointing to Lufthansa's liability.
"Details about this [the airline's] decision are not known to the Embassy", the head of the visa section in Harare had already written to Mr. Mulonga on 6 October 2017.
Yet, the German Federal Police maintains, both in personal communication with the presidency of the affected German church on 21 September 2017 and in the rejection letter of the disciplinary complaint against the tall white man of 1 March 2018, that their ILO had acted according to the instructions given by the head of the Harare visa section on the phone on the day of the incident.
That their ILOs only advise airlines on request and that the decision not to board the group had solely been taken by Lufthansa was, in turn, adamantly defended by the German government in its response to a parliamentary inquiry on 24 October 2017.
Two days later, on 26 October, the criminal charge for suppression of documents lodged against the tall white man by Mr. Mulonga's German partners was rejected as unfounded by the public prosecutor's office. The rejection literally states that the tall white man had indeed prevented the group from travelling but that he had followed orders from Harare and could hence not be personally indicted.
The most masterly pirouette of counterfactual diplomacy in this legal charade was however demonstrated by Walter Lindner, permanent state secretary at the Foreign Office since his recall as ambassador to South Africa early 2017, in a letter to the German church hosts on 2 October: the markings of the group's visas with the handwritten word "cancelled" did in fact and after all not at all constitute a cancellation of the visas and the group could indeed still proceed with flying to Germany.
So far, the Zimbabwean group has not been to Germany yet and there has not been any court trial, nobody has been held accountable for what happened, no compensation has been paid to them and their church partners in Oranienburg.
The rectangle delineated by the intricate bordering and buck-passing practices between the airline, the ground handling company, the German embassy and the German police could be described, at best, as a civil-law cover-up for administrative liability aiming at the legal limbo in which travellers singled out by arbitrary pull-outs are left in.
South African complicity?
Yet, the EU-sanctioned lack of compliance with fundamental principles of the rule of law in dealing with passengers on the side of European authorities and multinational companies may only be one aspect of the lawlessness of Germany's border in South Africa.
There is no explicit mention of the activities of German ILOs on South African soil in any bilateral agreement between the two countries. There also is no other publicly available document with which the government of South Africa has ever formally and explicitly allowed German authorities access to the so-called airside (the transit area behind the host country's last passport controls) of any of its international airports.
The South African Treaty Section of the Office of the Chief State Law Advisor at the Department of International Relations and Cooperation stopped communicating with the author at her enquiry whether the South African government winks at German police curtailing, in cooperation with domestic and foreign airlines and multinational ground handling companies, the constitutional right of everyone to free movement on its territory - which includes the right to leave the country (Section 21).
Does the mere accreditation of foreign police as embassy staff by the host country suffice to justify the infringement of the Constitution of South Africa? Does Section 2, the supremacy of the Constitution, apply at all?
Should the German government legitimise the executive-effect presence of its police at the boarding gates by applying the contestable notion of no man's land to the airside of the international airport, then how do the governments of Germany - and South Africa - justify the activities of the same members of the German executive authorities on the landside of O.R.Tambo International Airport where the tall white man has been observed by the author interacting with employees of other private security companies as well? Annex 9 of the Chicago Convention, which makes recommendations on the presence of ILOs at international airports, has no legally compelling effect on signatories.
"My heart still (... ) today bleeds with a million questions", Mr. Mulonga says. "We hope somehow justice to prevail."
The South African authorities and the other actors involved may well be forced to give answers, if affected travellers join up for class action.
 A pseudonym is used to protect the informants' privacy and to not aggravate their exposure to unfair and unlawful treatment at the hands of the gatekeepers of their mobility. All key informants have consented to the publication of this article and the author wishes to thank them for their trust and collaborative efforts. The author also is indebted to a handful of reviewers. All content and any errors are the sole responsibility of the author.
 The author is in possession of all legal communication mentioned.
* Olivia Klimm is a PhD candidate at the Department of Social Anthropology at Freiburg University, Germany. Further testimonials of pull-outs at international African airports are most welcome at olivia[dot]klimm[at]ethno[dot]uni[hyphen]freiburg[dot]de.