An employee of a weed dispensary in the Dutch city of Maastricht approaches three nervous tourists with a routine question. The apparent leader of the group – French tourists hoping to get into the Maxcy's coffeeshop – hands over a passport and a letter, while his two friends peek inside to take in the dispensary's interior. They seem to be on their first visit.

After the security guard looks at the letter, the first guy is allowed in: he was able to prove that he lives in the Netherlands and is above 18 years of age. It's now the turn of the other two.

The Maxcy's employee doesn't speak, just stretches out his hand and waits for a letter that includes a Dutch address. The two French guys try to act surprised, but they know the deal: if you can't prove you live in the Netherlands, you're not allowed into any weed dispensary in Maastricht.

"We're visiting our friend for the weekend," explains Jacques, who says he'd rather not give me his last name. "We figured we'd give it a try. Now, he'll have to get the weed and we'll smoke the joint somewhere outside."

The last few years haven't been easy for weed-loving tourists in the Netherlands: are they allowed in Dutch dispensaries or not? The confusion is understandable. The so-called ingezetencriterium – which roughly means "inhabitant criterium" – is a Dutch policy meant to deter drug tourists, and has gone through many iterations since it was first conceived. The rule was implemented on a national level in 2012 after a local issue turned into an international controversy.

Maastricht is located in the southernmost tip of the Netherlands. To the west, the city borders Flemish-speaking Belgium, while Germany, France and Luxembourg are all within driving distance. Maastricht is one of the oldest cities in the Netherlands, which is partly why so many tourists are attracted to it. Mostly, these tourists are German retirees and couples looking to sample "vlaai" – the famous local pie – but there's another type of visitor that locals are less happy about: those who show up specifically looking for weed.

"The dispensary crowd became a public nuisance," explains Gerd Leers, former mayor of Maastricht, who noticed around 2007 that the issues around dispensaries had turned into a local political issue.

Leers represented the CDA, a conservative party, but maintains a fairly liberal stance in the debate about the Dutch policy of tolerating cannabis by penalising production, but allowing sales in places called "coffeeshops".

"I think it's hypocritical," says Leers. "It forces coffeeshops to obtain their weed illegally, and for an administrator that's a very difficult thing to deal with."

Because of this, people who've never stepped foot in a coffeeshop often automatically assume they're fishy. Residents of neighbourhoods where dispensaries are located had trouble finding parking and were exasperated because there was always trouble of some sort – mostly caused by dealers who hung out on the surrounding blocks.

"It was dispiriting," sighs Leers. "At times, people visiting coffeeshops were followed by these guys from the moment they crossed the border. [Dealers] didn't just want to sell weed, but also different kinds of hard drugs."

A sign outside of coffee shop Toermalijn. Photo: Roos Pierson.

A solution was floated: what if the weed dispensaries were moved outside of the city centre? Leers was in favour: "We considered an industrial area close to the motorway. There, we could control things more easily and the city centre wouldn't be bothered anymore."

A consultancy firm, hired by the city, mocked up a digital image of the future exit on the motorway to a "Coffee Corner". Meanwhile, just across the border, Leers' Belgian colleagues couldn't believe what they were seeing.

"Those coffee corners would become like a McDrive for cannabis," says Mark Vos, mayor of the nearby Flemish town of Riemst. "Quickly hop off the A2 freeway, get your weed and get back on the road. Maastricht was going to export their policy of drug tolerance to neighbouring counties, and we were not interested in that."

Vos banded together with two other Belgian counties and one Dutch-allied town. Together, they sued to stop the Maastricht Coffee Corner from ever seeing the light of day.

This turned a local tiff between neighbouring counties into an international issue. The Dutch authorities were embarrassed when they had to face their Belgian counterparts in Brussels, who had never been too positive about the liberal drug policies in the Netherlands to begin with. Politicians at a national level got involved, and suddenly Maastricht's parking problems were national news.

The Dutch government is highly sensitive – if not outright allergic – to international criticism of its drug policy, which is made up of compromise upon compromise. The Belgians were clear in their lawsuit: "We thought the tolerance-based policy had failed and we didn't want it in our towns," Vos explains.

The Dutch Secretary of Justice at the time called Mayor Leers to ask about another possible plan: a special pass to visit coffeeshops, which only permitted access to people who had signed up and were registered. The plan was to perform an initial test in the southern part of the country, after which this "weed pass" would be introduced nationwide. The pass would end the anonymity associated with coffeeshops, but would at least keep drug tourists out.

Leers agreed to give it a go, because "all ideas were welcome". Shortly after that, new mayor Onno Hoes took over, and continued Leers' work of implementing the new policy.

On the 1st of May, 2012, the southern border provinces of Zeeland, Brabant and Limburg kicked off the trial. Maastricht ran an ad campaign to inform the French speaking parts of Belgium about the new policy, including a YouTube video with a punk rock soundtrack and the fitting title "New rules no drugs French.mp4".

Aragon Verhaaren – who managed the coffeeshop Toermalijn in Tilburg, in the southern province of Brabant, at the time – says: "We had to implement a scanning system, which involved taking pictures of customers. People didn't want that at all – some stayed away completely, others started buying on the street. Within a day, I went from hundreds of customers to only three. Three!"

Lisa Lankes, who owns the coffeeshop Pink in Eindhoven, in North Brabant, is still angry about it: "About 8 to 9 percent of our customer base came from Belgium; there were no big problems here, but we were still forced to implement the pass."

It didn't take long to conclude that the weed pass was a complete bust. Both locals and tourists were avoiding coffeeshops, which opened up a new market for drug dealers. Before long, hash, cocaine, weed and pills were available on street corners in Brabant and Limburg.

On a national level, the project to combat "public nuisance and criminal behaviour" had so much political prestige attached to it that Ivo Opstelten, then-Secretary of Security and Justice, headed to Maastricht with cameras in tow to get a firsthand look at how the weed pass was functioning.

When he arrived, he saw that his new rules had created a mess, so decided to do away with the weed pass and introduce the "inhabitant criterium" – allowing only those who can prove they're residents of the Netherlands to buy weed. Locals, international students and expats were welcome, while tourists would be banned. A trial run of this new idea would start in towns along the border, and afterwards the new policy was to be rolled out nationwide.

Meanwhile, international media reported that Amsterdam would soon be shutting the doors of its famous coffeeshops to tourists – just like the government had planned. However, it never got to that point, because Eberhard van der Laan, then-mayor of Amsterdam, made a deal with the Secretary of Justice. In return, dozens of coffeeshops near schools were closed, to prove the mayor was taking issues around drugs seriously.

Belgian Mayor Vos was very happy with the outcome. "It's great that this turned into a national issue – it should actually be a European issue," he says. "The Netherlands are like a supermarket for drugs. The policy of tolerance has failed."

Cities in the Netherlands' border provinces that have the i-criterium for "coffee shops" in red, and some examples of towns where tourists are welcome to buy weed in green. Illustration by Dymphie Huijssen.

These days, Dutch municipalities can decide for themselves if they want to uphold the ingezetenencriterium – or "i-criterium" – and bar tourists from their coffeeshops. In Rotterdam, Amsterdam and Groningen, tourists are welcome, while in Brabant and Limburg the rules differ in every town. Sittard, in Limburg, for instance, decided for a while to allow everyone, but when it was hit by a wave of tourists trying to evade the more restrictive policy in Maastricht, Sittard decided to follow suit.

In the more liberal towns of Eindhoven and Tilburg, city councils decided to welcome back tourists. The weed seekers don't cause much trouble, and people like Achmed from the French city of Lille are happy about it. "I like being able to do this out in the open without making a big deal out of it," he says, pointing at his joint. "Where I'm from, they really make an issue of it, and in the Netherlands I don't feel discriminated against."

Certain towns complain that the i-criterium still drives tourists into the arms of street dealers. But according to Belgian mayor Vos, the policy works: "It's been very successful. We see a lot less drug runners, and we can now put our police force to work to catch drug users and dealers in our own towns."

The lawsuit that put the problem on the national agenda was lost by the Belgian towns in 2014; the judge declared the complaint inadmissible, because the problem was local to Maastricht. Meanwhile, cannabis policies are back on Dutch politicians' agendas. After years of deliberating, the current government has reached a new compromise: an experiment with legal weed will have a soft launch in ten municipalities. Keeping tourists out is already an integral part of the new concept law.

Read more stories from VICE.com's series about how the national borders dividing and surrounding Europe affect the lives of the people living near them.

Don't miss the next issue of VICE Magazine later this month, dedicated to the global exploration of borders, investigating why we've imbued them with so much power, and what happens when those lines aren’t visible to the naked eye.