PHNOM PENH, Cambodia — On the books, marijuana is illegal in Cambodia. But on the streets — in particular, the capital’s main riverside promenade — travelers will find a poor man’s Amsterdam.

Phnom Penh’s downtown dealers are unabashed. After nightfall, they line Sisowath Quay, about a dozen blocks of Cambodia’s finest riverfront real estate. Foreigners on an evening stroll down the main drag pass through a gauntlet of pot propositions: “You want smoke? Marijuana?”

They do not bother to whisper.

Those skittish of street deals can duck into one of several pizza shops, “Happy Herb’s Pizza” or “Pink Elephant Pizza” among them. They are cannabis dispensaries concealed under a thin veil of innuendo. Pizzas ordered “happy” are dusted with flakes of ganja.

The effect: a high that fogs thought, puts lead in your footsteps, stokes the appetite (perhaps for more pizza) and throws a dull haze over the next 24 hours. That’s right, 24 hours.

Traditionalists can order 10-gram bags from the kitchen stash for $20.

If the pizza shops aren’t convenient enough, smokers can stay indoors and call the delivery hotline.

“Just don’t smoke it on the street. That’s all,” said a server at one of Phnom Penh’s downtown pot-and-pizza joints. “Don’t worry about police. Police know everything.”

Nations such as Portugal and the Netherlands have the most prominent reputations for rejecting the United States-helmed “War on Drugs” approach in favor of liberal narcotics laws. Latin American countries including Mexico and Colombia, bloodied by cartel carnage, have pushed the trend further by decriminalizing small amounts of pot.

But Cambodia — like Pakistan and Egypt — belongs to a lesser-recognized category: countries that have adopted US-style pot laws under White House pressure but seldom enforce them. Its modern marijuana market offers a case study in de facto decriminalization.

Drug policy experts contend that nations such as Cambodia, impoverished and deeply reliant on US aid, must feign an anti-cannabis stance — even in the absence of political or popular support for police action against pot.

“If they didn’t, there would be serious backlash from the US,” said Benoit Gomis, a narcotics policy analyst with the London-based Chatham House research institute. “So is it worth making a big fuss about drug policy when you receive assistance for so many other things? Like your economy? That’s a diplomatic calculation they have to make.”

The world says, legalize it!

Across the globe, pot tolerance is trending up. The list of nations that have to some degree decriminalized cannabis possession in small quantities grows by the year. An incomplete roster now includes Argentina, Australia, the Czech Republic, Colombia, Portugal, Switzerland, Spain and Uruguay.

In Italy and parts of Australia, users may grow a small amount on their terrace. In parts of India, state-managed shops in certain provinces can sell “bhang” — hash balls — and mystics can indulge with impunity. In Spain’s Basque Country, smokers are free to join “cannabis social clubs” that cultivate their own pot to meet members’ needs.

Mexico is pursuing a radical change in its approach to drugs. After a six-year battle against gangs and traffickers that cost some 60,000 lives, the country’s new president has announced a new emphasis on prevention. The government will spend $9.2 billion on social programs — including infrastructure, construction and longer school hours — in Mexico’s 251 most violent neighborhoods.

“It’s clear that we must put special emphasis on prevention, because we can’t only keep employing more sophisticated weapons, better equipment, more police, a higher presence of the armed forces in the country as the only form of combating organized crime,” said President Pena Nieto in announcing the program.

Even in brutally authoritarian North Korea, police squads execute meth abusers while ignoring marijuana use, according to reports from Open Radio for North Korea and NK News.

But perhaps the boldest challenge comes from South America’s Uruguay, where lawmakers are considering government-run marijuana emporiums. The proposed “National Institute of Cannabis” would sell pot at below-market rates, undercut the street traffickers and funnel the proceeds towards drug treatment centers.

This global loosening of pot laws is testing rigid United Nations drug conventions, which favor US-style prohibition and still regard marijuana as a dangerous narcotic.

“The starting point of the drug convention is that drugs are bad,” Gomis said. “It says that if people are allowed to consume drugs legally, they’ll consume way more drugs. And that will lead to more death and violence and social disorder.”

The UN conventions are clear: Countries that have signed on (as almost all sizable countries have) are not permitted to start up a regulated marijuana trade in the vein of booze and tobacco markets.

“Any shift away from the predominately zero-tolerance approach of the UN treaties generates a number of oppositional forces,” said David Bewley-Taylor, a drug policy specialist at Swansea University in Wales.

“The reach and well-established nature of the global drug prohibition regime,” Bewley-Taylor said, “ensures that most states are reluctant to deviate ... and risk being labeled by the international community a rogue state.”

But that standard is shaken now that the US has developed its own rogue states: Washington and Colorado. Last fall, both passed referenda compelling the outright legalization of marijuana — although it remains to be seen how this will work while the federal government still bans the herb. Moreover, medical marijuana is allowed in a total of 18 states. America’s position to “exert pressure,” Bewley-Taylor said, “has been undermined by the situation in Washington and Colorado.”

And politicians, long shy about an issue that could alienate soccer moms, are increasingly speaking out. Recently, New York Mayor Michael Bloomberg announced that people busted with small quantities of pot in the city will no longer spend the night in jail. He also called on Gov. Andrew Cuomo to loosen marijuana laws.

The world, it seems, has reached a tipping point in the drug war.

Flouting a US ultimatum

In the 1990s, when war-torn Cambodia was even more unruly than it is today, marijuana was traded openly. Vendors in Phnom Penh’s downtown markets freely sold fat pillows of marijuana weighing a kilo or more. The herb grows naturally in the tropical nation of 15 million people, many of whom know pot as an old-timers’ habit or an ingredient in upcountry soups.

But when the US and other Western nations began showering Cambodia with aid in the 2000s, authorities suddenly deemed marijuana a nuisance and swept it from public view.

“The US gave them an ultimatum,” said a UN drug analyst speaking on condition of anonymity. “They said, ‘You can either have foreign aid or legal cannabis.’”

Today, drivers of “tuk-tuks” (motorized rickshaw taxis) are Phnom Penh’s go-to source for ganja. As in neighboring Thailand and Laos, tuk-tuk crews often act as intermediaries between travelers and vice: prostitutes, ganja or harder narcotics.

The pushy types park their tuk-tuks and work the riverside gauntlet. Some will advertise their wares by waving a still-fragrant, half-smoked joint under a tourist’s nose. In plain view, they often swap US cash for bags of so-called “skunk,” marketed as a higher quality of pot.

But Chhon — plump, smiley and 30-something — is a less aggressive breed of downtown Phnom Penh dealer on wheels.

“I just ask a person if he wants a ride and then talk about ganja in the tuk-tuk,” Chhon said. “A lot of people want ganja. The police know what we do. If they catch you, they might ask for some small money but they don’t stop it.”

That doesn’t mean top authorities don’t talk tough on pot. The national drug czar in 2008 went so far as to declare to a regional news outlet, The Mekong Times, that “marijuana is no longer available in Cambodia” after crop eradication campaigns.

But the government’s own drug figures render such bold pronouncements absurd.

For four years straight, Cambodia hasn’t managed to report arrests for pot possession to the regional UN narcotics database. In the last reporting year, 2008, authorities reported a scant six marijuana-related arrests.

The nation’s crop eradication efforts are similarly meek. In all of 2008, amid the run up to the then-drug czar’s proclaimed end of pot in Cambodia, drug police destroyed a mere 177 square meters of marijuana fields — a size comparable to a typical three-bedroom apartment. Even that was a bonanza compared to the most recent eradication figures: just 200 or so cannabis plants destroyed in 2011, according to government figures.

“We’ve noticed in the past five or six years, the quality of reporting coming from Cambodia dropped,” said Tun Nay Soe, a senior officer with the UN’s SMART program, which monitors global drug use trends. “We know they have plantations of cannabis that are grown commercially. But methamphetamine is much more of a problem there.”

Chhon is somewhat mystified by young foreigners’ deep appreciation for marijuana. According to a UN survey, marijuana is the fourth most-popular drug among Cambodians: crystal methamphetamine, meth and even inhalants are more widely consumed.

“Ganja is not so big for Cambodians,” Chhon said. “Most people with money want ice.”

This is Southeast Asian code for crystal meth, which grows more popular by the year. Its jumpy highs and wretched comedowns are totally unlike the marijuana high and the substance is now classified as the region’s top threat among regional drug agents.

But even Cambodian authorities indirectly concede that the pot prohibition stance in Washington, DC, never really took hold.

“The extent to which cannabis is used in Cambodia is unclear due in part to a level of tolerance for its traditional consumption,” the National Authority for Combating Drugs stated in an annual report.

This “traditional consumption” — sprinkling marijuana in select dishes — is also prevalent in surprisingly strict places: communist-run Laos, and the wilds of Indonesia’s Aceh province, the only Southeast Asian enclave controlled by Islamic Sharia Law.

“Even in my country, Myanmar, it’s quite normal for people to put cannabis in their food as a spice,” Tun Nay Soe said.

Whether Cambodia and other US aid-reliant nations keep up their anti-pot charade may largely depend on whether more influential nations can take on the prohibition regime. Officials in Mexico and other Latin countries, the chief targets of America’s foreign drug war, could feel emboldened to loosen pot laws further as select US states opt for legal pot sales.

“There’s been a realization almost everywhere that criminalization and the hard approach on drugs just isn’t working,” Gomis said. “It creates a bigger black market. It creates more violence.”

But Chhon is ambivalent about the future of Cambodia’s pot laws. After all, US interference shifted pot from the market stalls to the streets, where he can sometimes make $20-25 — no small sum in Cambodia — selling just one overpriced $40 bag to foreigners.

“Now, you can still buy ganja, you can smoke. There is still no trouble and no problem,” he said. “Just stay away from the street and don’t be stupid.”