Yet my country, Australia, has discovered the vaccine to such gun massacres. In April 1996, six days after a misfit shot dead 35 people at Tasmania’s historic Port Arthur tourist site, our arch-conservative-led government passed the National Firearms Agreement, outlawing all civilian access to semiautomatic rifles and pump-action shotguns.

Will the Trump administration roll out Australia’s vaccine against massacres, or will they flush it down the toilet?

In the 18 years between 1979 and April 1996, Australia experienced 13 mass shootings (defined as having five or more victims, not including the perpetrator), in which 104 people died. In the 21 years and five months since the Port Arthur massacre and the passage of the law that followed swiftly afterward, we have seen precisely none.

Pure evil, as U.S. President Donald Trump described the killer, is inevitably found in every country. But when evil men have easy access to rapid-fire lethal weapons—those invariably chosen by pathetic fantasists wanting to make their mark—the outcomes are predictable.

Assault weapons turn nasty incidents into massacres. There are no drive-by stabbings. A man running amok in a crowded space with a knife, machete, or baseball bat may kill a few and injure some more. But who would rather not take their chances against an assailant with a knife than one with a machine gun?

Like the Las Vegas killer, the Port Arthur gunman had no record of violent crime or mental illness history. Like all but two of Australia’s mass killers before him, he was a law-abiding gun owner. Solutions predicated on predicting who will later be violent have eggshell-thin evidence supporting them.

A 2013 study of 27 developed nations found “the number of guns per capita per country was a strong and independent predictor of firearm-related death,” with the authors concluding that their study “debunks the widely quoted hypothesis that guns make a nation safer.”

Polling at the time of Australia’s law reforms indicated that 90% of Australians wanted serious changes introduced. Our National Rifle Association-equivalent gun lobby could only fire political blanks at this. The ban saw a time-limited income tax levy imposed to enable the market price buyback of some 750,000 now banned weapons. Self-defense was also declared an unacceptable reason for purchasing any gun, with all licensed shooters thenceforth needing affiliation with a sports shooting club or authorization from land owners to hunt.

Australia and the U.S. share many cultural affinities. Firearm ownership is common here, but is not unbridled as it is in the U.S. The U.S. has 13 times Australia’s population, 134 times our total firearm death rate, and 27 times our gun homicide rate.

Australia’s gun ownership reforms were introduced explicitly to reduce the likelihood of mass shootings. In that they are a triumph. But the removal of some 750,000 semiautomatic and rapid-fire weapons from the community may have had collateral benefits on trends in non-mass firearm deaths as well.

Australia’s 104 victims of mass shootings represent a small fraction of all people intentionally shot dead in Australia between 1979 and today. For every person shot in a mass killing, 139 others commit suicide or are murdered with guns in incidents in which fewer than five people die (most commonly one or two are killed).

Not only did massacres stop, but total firearm deaths did as well. From 1979 to 1996, the average rate of total firearm deaths was 3.6 per 100 000 people, whereas from 1997 to 2013, the mean rate was 1.2 per 100,000.

Australia is far a safer place today than it was before we took action to limit the availability of guns. If the U.S. doesn’t reform its gun laws, it will stay exactly where it is.

Simon Chapman is an emeritus professor in public health at the University of Sydney. Follow him on Twitter.