It had only been a few days since the latest crackdown on Cambodian migrants working in Thailand – more than 1,000 illegal workers were sent back in only three days in early March before attention once again turned to this slow burning international conflict.

A few months before, thousands more suffered a similar fate. Moreover, these were the lucky ones. According to a Ministry of Interior report, in 2016 “Thai soldiers shot dead two and injured seven Cambodian citizens who illegally crossed the border, and arrested 293 people, including 45 females”, with a spate of violence in December of last year prompting emergency talks between top leaders to discuss a border that remains “a killing machine” according to human rights groups.

Nevertheless, the issue runs far deeper than the disproportionate responses of a handful of border police. The key dissonance is not between Thai and Cambodian authorities’ view of their mutual border, but between the official view of the Thai-Cambodian migration system and the perspective of those who use it.

Though they appear to debate and discuss their shared issues, both sides persist in a consensus that criminalises much of the everyday movement taking place between their two countries, rather than recognising it for the informal, but systematic and bilaterally cooperative institution that it is.

Indeed, the Thai-Cambodian cross-border economy is vital to both sides. Immigrant workers have been estimated to contribute about 1 percent of real GDP growth to the Thai economy and the figure is almost certainly growing as the volume of migration continues to expand. At the same time, the flows of money sent back by workers in Thailand have become intimately intertwined with the Cambodian rural economy.

The labour-sharing systems that sustained rural villages in more isolated times have increasingly given way, in this era of high and rising environmental risk, to faster, more capital intensive farming methods that require income from beyond the household.

The mutual reliance of these neighbouring economies reveals a fundamental disjuncture between the economics and politics of the Thai-Cambodian border. On the one hand, it is a deeply co-dependent and thriving cross-border economy; on the other, two separate sovereign states separated by an invisible but deadly border.

These realities one official, one actual are mutually exclusive, but those who pay the price for their discordance are not planners and logicians, but ordinary Cambodians, pressed by circumstances into joining an old and well-established system of international mobility.

Far from the clarity of the thick black lines that divides the two nations in theory, the border separating Cambodia and Thailand is a living entity, defined more by personal relationships, networks and tradition than legality. Indeed, legality is itself a relative concept here. Although vast numbers of Cambodians living on the east side of the border cross regularly to participate in agricultural, construction, or factory labour, a recent study – forthcoming in the Singapore Journal of Tropical Geography – has found that only 3.6 percent of current or former migrants possessed a full set of documentation for work abroad.

By the clearly defined letter of international law, then, more than 19 out of 20 migrants to Thailand from some areas of Cambodia are working as illegal immigrants. However, to view the situation thusly would be to grossly misrepresent the situation.

Whilst around half of the remainder possess no documentation, a further 40 percent possess a “bat”, a temporary work permit facilitating employment of foreign nationals subject to a stringent set of conditions including regular renewal, weekly reports to local police authorities and of course the ability to present a valid passport.

The long hours and limited freedoms characteristic of most forms of migrant labour makes fulfilling any let alone all of these conditions impossible. Very few possess both a visa and a work permit and even among those who do, even fewer renew it regularly or submit to the burdensome registration conditions of which many are unaware.

However, that so many Cambodians spend hundreds of dollars processing various combinations of documents either through official or, far more commonly, unofficial means should not be dismissed as ignorance. Along the Cambodian border, as in many parts of the world, borders simply look different to those who use them. Official channels are not only prohibitively expensive and often distrusted, but also physically and institutionally distant. Informal ones, by contrast, usually in the form of brokers and middlemen, are human, accessible and offer solutions in simple terms.

Rather than the scattered outposts of government administration in far western Cambodia, or its central base hundreds of kilometres away in Phnom Penh, it is these people a vast network of drivers, salesmen, managers and employers of both Thai and Cambodian origin that are the face of authority for most of those who use the border.

Consequently, for those who participate in the informal economy of cross-border migration, it is not the government that sets the rules of documentation, but the known, trusted and – crucially – physically present broker who stands in front of them. If he or she says, as brokers are wont to do, that “with documents you can go everywhere freely, but without them you will be always looking around, always fearful”, then a migrant has little choice but to believe them.

Furthermore, while the narratives of documentation offered by brokers may not tally with the legal reality, this does not make them untrue. In the Thai-Cambodian migration system, as in many others, the people who use brokers to cross a border remain within their influence on either side.

Repayment plans for documents are arranged and employers are selected even before leaving the village in most cases. Similarly, brokers offer protection from authorities on both sides, although the extent depends on the cost of the service provided: the more you pay, the safer you are.

Those who choose the basic package of brokerage run the greatest level of risk – “running all night through the forest” or “hiding in the back of a truck” to escape the authorities. And it is this group the poorest farmers, the deepest in debt –whose wages will be both lower and docked more punitively to pay for the cost of their trip. Indeed, there is a hierarchy of prices for work in different industries. As migrants themselves explained:

‘[I]f you want work in construction it will cost you 3,000 baht [$92], but if you want to work in a garment factory, it may be 4,000 baht [$123]’ (Returned Migrant 13, Svay, 14/08/2014).

In this way, both the migration process itself and employment on the Thai side reflect the entrenched financial inequalities of life in Western Cambodia. Subtle variations in rural livelihoods create uneven opportunities across the border and these differences in working conditions in turn reinforce inequalities at home. Poverty on one side of the border means poverty on the other as the ever present flows of people linking the two countries keep migrants and their households constantly and dynamically linked together – but for both sides migration means life.

For those who use it, then, this vast migration system is a cohesive, living organism; it is the border – impotent and dead atop a thriving economic entity that is the unnatural element. Cambodians do not migrate illegally because they wish to, but because illegal migration is practically the only course of action on offer. The much vaunted One Stop Service Centres set up in the wake of the 2014 exodus are only a small part of the solution. While they help to streamline the complex process of obtaining documentation, it is only documentation that they offer, without the linkages to employers, transportation, or guidance that are vital to a successful migration.

For the poorest households that are the primary source of undocumented migration from Cambodia, it is these services that matter more than any other. Even if they can obtain documents, most potential migrants cannot cross a border speculatively looking for work, nor can they afford the chance of failure given the investment of time and resources that any migration requires. Consequently, “guarantees” of work however dubious are invariably preferable to the uncertainties of legality. Nevertheless, the tradeoff for choosing the only economic pathway available to many worse-off Cambodians is the risk of exploitation, deportation and death.

This everyday injustice emerges not from the brutality of police patrols but from the highest levels of international policy: where legal frameworks reflect the two countries’ economic inter-linkages so poorly, conflict is inevitable. As long as both sides fail to acknowledge the reality that they are vital to each other’s ongoing economic health, the convenient political myth of mutual isolation will continue to see Cambodians disadvantaged, exploited and killed.

Rectifying this means first recognising that the Thai-Cambodian border is not a natural national edifice punctured by opportunistic criminals, but a largely arbitrary division of a longstanding system of mobility sustained by a shared history and culture of mobile livelihoods.

As long as accessible migration services – in the form of documents, but also linkages to employers, and affordable and practical transportation – continue to be the sole preserve of “criminal” agents, then it will continue to be the poorest Cambodians who are criminalised and made to run the starkest risk to their lives and livelihoods. It is time for these two states to give back something to the embattled migrants that link and enrich them.

Dr Laurie Parsons has been an academic researcher of Cambodian mobile livelihoods since 2008, conducting large-scale projects for Transparency International, Plan International, Save the Children, CARE International, ActionAid, the IDRC and the Royal University of Phnom Penh among others.