Swiss-themed gun holsters are displayed in a glass case during the 45th edition of the Arms Trade Fair, in Lucerne, Switzerland, on March 29. (Stefan Wermuth/AFP/Getty Images)

BERLIN — In some countries, pushing through gun reforms after major terrorist attacks or mass shootings has proved to be more difficult than in others. While the United States remains far from any substantial changes, New Zealand banned semiautomatic assault rifles and military-style weapons less than a week after the Christchurch terrorist attack in mid-March.

The move echoed a similar, but far slower, 2017 move by the European Union to toughen firearms laws in response to the 2015 Paris attacks that left 130 dead.

In a bloc of 28 (soon to be 27) member states, agreeing on joint reforms proved more difficult than expected. The passed reform ended up being weaker than initially proposed, with various exceptions for hunters or members of firearms clubs, for instance, who will continue to be able to own semiautomatic rifles and handguns.

The reforms will still make it more difficult for civilians to legally obtain them and — perhaps more importantly — create uniform rules for the registration of such weapons, which is especially important in the borderless Schengen zone where arms traffickers have so far found loopholes in abundance.

Later next month, Swiss voters will decide if those rules should also apply to Switzerland, which, while not part of the E.U., tends to follow the bloc’s rules. Switzerland has long held a unique status in the Western world for having one of the world’s highest per capita gun ownership rates but very few shooting deaths. To the Swiss, semiautomatic rifles and other weapons were long a sacred part of their culture. After the end of their mandatory military service, about half of all conscripts would take their military-issued weapons back home, in what Swiss leaders long argued was an effective way to uphold the country’s ability to defend itself. But the ratio of former soldiers taking their weapons home has fallen to about 10 percent, amid other signs that the Swiss weapons culture is changing.

Under existing law, individuals flagged as potential threats already are barred from accessing firearms and have to hand already purchased weapons over to authorities.

Next month’s referendum on tougher weapons laws could become a turning point in the country’s gun ownership history, after years of gradual changes — as well as determine Switzerland’s future relationship with the E.U. In the long run, a pro-reform outcome of the referendum would significantly weaken the country’s gun lobby and could pave the way for more extensive reforms that would have been unimaginable a decade ago. In the short run, however, little would change for Swiss gun owners, who will still be able to purchase and own semiautomatic firearms and other weapons as long as they can prove they regularly use or train with them.

Switzerland effectively shaped the E.U.’s gun reforms, even though the country is not part of the bloc. It is, however, to a large extent part of the single market and borderless Schengen zone, and an associated member of those agreements. Switzerland’s lobbying efforts in Brussels over these laws may also be a lesson to Brexit supporters in London. One of the key concerns of opponents of what’s known as soft Brexit — in which Britain could to some extent follow Switzerland’s example — is that Britain may then be bound by E.U. law with no power to shape it.

But Switzerland’s coming gun reform referendum proves the bloc is as much a political union as it is a legal one, with leeway to adapt its rules when needed. Aware of the backlash that a total ban on semiautomatic weapons for certain groups of civilians would have had in Switzerland, the E.U. made specific concessions, including a rule that permits former soldiers to continue to take their firearms home.

While the E.U., from its own perspective, may have made it as easy as possible for Swiss voters to accept tougher gun laws in next month’s referendum, there is still substantial opposition to the plans. A number of Swiss right-wing groups, along with firearms clubs, associations and veterans groups, have mobilized against the E.U. changes. On their campaign website, they argue that the E.U. directive would force them to “give up our right to own weapons.”

“This is ridiculous, it is crazy, and it is scandalous, and everyone knows it,” the groups said. To them, opposition to the gun reform appears to be part of a broader fight against the European Union.

“If we don’t reject such demands, we signal that we’re easy to hassle,” they wrote, before referring to the country’s decision to join the E.U.’s Schengen zone in 2005.

Such battle cries against the European Union may have mobilized a majority in Britain to vote in favor of leaving the bloc in 2016, but they are more likely to have the opposite impact in Switzerland next month because the stakes in the vote are about far more than guns. If Swiss voters vote against the E.U. gun directive, the country’s de facto membership in the single market and Schengen zone would end later this year, unless the E.U. intervenes.

Much of Europe may not have noticed so far, but a rejection of the E.U.’s reforms during next month’s referendum could result in a second no-deal Brexit scenario — this time in Switzerland. Swiss police officers would eventually lose access to European data-sharing agreements, trucks would pile up at the borders and the country’s GDP may drop by 3.7 percent, according to a parliamentary assessment of the expected economic damage.

A look at Britain’s initial shoulder-shrug over such scenarios and the gradual realization that they might be true could provide a cautionary tale on May 19, when Swiss voters will head to the polls.

Meanwhile, E.U. supporters in the country are busy framing a vote on firearms as a vote on Switzerland’s future: a country with either prosperous gun stores, or with a prosperous economy.

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