Hendrix (Jimi) gazes down with bloodshot eyes from a portrait on the wall. Jagger (Mick, “Gimme Shelter”) groans on the sound system. And sitting joyous amid clouds of swirling smoke at the 420 Cafe is Savage (Jason, of Morgantown, W.Va.), a tourist who arrived a few days ago on one of his frequent trips to the Netherlands.

He does not come for the tulips.

Yet even as he eagerly anticipates his turn on a joint the size of Texas in his pal’s hand, this 38-year-old visitor is troubled. Word is spreading fast through the United Nations of Stoners: For foreign tourists — generations of whom were drawn to this city’s open cannabis culture — these could be the last days of Purple Haze (or Lemon Larry, White Widow, NY Diesel, Space Cake and any of the other earthy-spicy morsels on this city’s extensive marijuana menus).

Enforcement of a new law banning all but Dutch residents from pot “coffee shops” started in southern cities in the Netherlands, where drug-related organized crime became one of the main drivers of the new regulations. Roadside signs put up by authorities across the south now bluntly warn visitors, “New Rules, No Drugs,” with at least one cafe shut down by police for serving foreigners and several others closing voluntarily in protest of the tourist ban.

But for global Bohemia, what truly matters is the second phase of the plan: On Jan. 1, the ban is scheduled to go into effect across the rest of the country — the 250 cannabis cafes of Amsterdam included. Just like that, a thriving scene where aging hippies toke with the Occupy movement’s tweeting classes, where themed pot cafes seem to teleport you to Paris of the 1890s, Casablanca of the 1920s, Haight-Ashbury of the 1960s, could vanish in a puff of smoke.

“This is huge,” Savage moaned, head in hands. “I mean, how could they do this to us?”

Rolling back tolerance

From the macro perspective, the move could deal a blow to global efforts to legalize marijuana — a movement that through legal medicinal sales has been making steady gains in the United States, where even televangelist Pat Robertson has come out in favor of treating cannabis like alcohol in the eyes of the law. Now, opponents could seize on the rolling back of tolerance by even the accommodating Dutch as evidence that legalization might not work as well as advocates claim.

But for weed lovers of the world — a group for whom Amsterdam became a sort of rite of passage and a liberation from the confines of home — the personal loss could be incalculable.

“The coffee shops became extensions of your living room, a place where you find a 65-year-old Brazilian lawyer talking to a 20-year-old American backpacker, both relaxed and open because they’re smoking” weed, said Jonathan Foster, 40, a Rhode Island musician who in 1995 opened Grey Area, Amsterdam’s only American-owned cannabis cafe.

In his cramped space, Foster said he has helped the likes of Willie Nelson, Snoop Dogg and Woody Harrelson get high. “Nationalities mix, people bond. The idea that could go away is too much to imagine.”

A judge in The Hague ruled against a legal challenge to the ban last week, but cafe owners are appealing that decision. If their case fails, many owners say they will simply ignore the ban and hope Amsterdam city officials — who have publicly come out against it — will look the other way. They take stock in the fact that it took authorities 10 years before they truly began enforcing the official ban on alcohol and marijuana sales at the same establishments.

But with national authorities insisting on the ban, a cloud of another sort is suddenly hanging over Amsterdam.

Walk through the red-light district, where beckoning women in fishnets display themselves in dimly lit windows, pass the bigger cafes such as the Grasshopper and Homegrown Fantasy, and soon you come to the 420 Cafe, where you can always spot the first-timers. Fresh-faced young things bravely walk through the door. Bravery quickly fades. Is this really, like, legal? But eyes light up at the menu. Dude, no way. They’ve even got hash.

Bongs, papers and vaporizers (the “Rolls-Royce of toking”) are free with purchase, along with a dense atmosphere rich in THC (tetrahydrocannabinol). In one little corner, deep conversations (at least they seemed so at the time) are going on in English, Turkish, Spanish, French and Hindi. At the register stands Steven Pratt, 420’s budtender and sommelier of Amsterdam weeds, many of which are grown in the Netherlands and discussed with the same academic passion as wines in France.

The new policy would see cannabis cafes become members-only clubs, with “pot passes” to enter issued only to registered Dutch citizens and resident foreigners. But the idea of registration ­directly clashes with the notion of liberation being peddled at cafes, and many owners and Dutch clients insist they will simply refuse to comply.

Looking the other way

Technically, buying pot and hash in the Netherlands has always been illegal, but since 1976 a sort of “don’t ask, don’t tell” policy arose over possession of less than five grams. By the 1990s, pot coffee shops or “cannabis cafes” were issued “toleration licenses,” effectively allowing them to sell small quantities of soft drugs as long as they didn’t also sell alcohol. The opaque procurement of large stocks by cafe owners clearly violates Dutch law, but authorities simply look the other way.

Statistics show the rate of marijuana use in the Netherlands is actually lower than in the United States or Britain. The pushback against drug tourism came as a result of a rise in organized crime. Opponents say the Netherlands has become the wholesale supplier for illicit sales across Europe. In 2010 in the southern town of Helmond, for instance, a cannabis cafe was attacked with hand grenades, and the mayor and his family were forced into hiding after being threatened by suspected drug runners.

In recent years, Rotterdam and other cities have sought to curb cannabis cafes, with the current nationwide total of 650 about half the peak numbers in the 1990s. Nearly one-third of those are packed block to block along the pot-scented streets of central Amsterdam, where tourists account for up to 90 percent of the cliental at some establishments.

If the new law is rigorously applied here, cafe owners insist it will simply mark a return to the days of unsafe street-corner deals.

“You might hurt tourism and the cafes, but a few new guidelines are not going to stop people from buying weed in Amsterdam, trust me,” said Michael Veling, 56, owner of the 420 Cafe.

Special correspondent Marit Van Kooij contributed to this report.