Guns exist for one reason: to kill. Firearms allow murderers to act more quickly, easily, and frequently with exponentially greater casualties. Put simply: People with guns do much more killing than people without guns.

On Dec. 2, it only took the two shooters at the Inland Regional Center in San Bernardino, Calif., a maximum of three minutes to fire 65 to 75 rifle rounds. Firearms allowed them to attack indiscriminately and from a variety of distances, killing 14 people and wounding 21.

This is why "common sense" gun safety laws like stronger background checks, long holding periods, and revocation of illicit dealers' licenses aren't enough to adequately decrease the violence our country faces. These policies are vastly disproportionate to the scale of gun violence in America.

The United States firearm murder rate is about 15 times the average for all developed nations, according to data compiled by the United Nations. Looking at Great Britain, Australia, and Japan, we can study the ways in which sweeping gun-control policies have drastically lowered fatalities. Adopting similar legislation to reduce the number of firearms in the United States is the most certain way to combat gun violence.

The only firearms that can be owned by civilians in Great Britain are shotguns, manually loaded cartridge pistols, and manually loaded center-fire rifles. Police officers, military, and individuals with written governmental permission may own handguns. Police officers don't even carry firearms routinely. A prospective gun owner must demonstrate a "good reason" — including profession, sport, collection, and research — to possess a weapon. Self-defense is not sufficient.

In 1997, according to a Library of Congress website, U.K. civilians surrendered 162,000 weapons and 700 tons of ammunition through a six-month buyback program, a tactic that has been successful in several cities in the United States. In 2008 and 2009, firearms were responsible for the deaths of 39 people in Great Britain, accounting for just 0.3 percent of recorded crimes.

In Australia, automatic and semiautomatic rifles are illegal, but police and hunters may own semi-automatic handguns, Business Insider reported in 2013. A 1996 buyback program took approximately 650,000 assault weapons out of public hands. Homicides by firearm were reduced by 59 percent between 1995 and 2006, with no corresponding increase in non-firearm-related homicides. Nor did home invasions increase, despite there being fewer guns available for self-defense. Since 1996, there hasn't been one mass shooting in Australia.

Only air rifles and shotguns are legal in Japan. Applicants must take a class on gun regulations, pass written and practical exams, and provide medical proof of their mental health and drug-free status. Gun-owners are required to store their weapons in a locker and keep ammunition in a separate locked safe. They must submit to background checks, yearly inspections of the firearm, and retake classes and written exams every three years. Japanese civilians hold just 710,000 guns with 0.6 firearms per 100 people (the United States has 270 million guns — 88.8 per 100 people), according to the Washington Post. There are nearly 127 million people living in Japan but in 2008 there were only 11 gun homicides, the website Vox reported. In 2011, there were none.

Following aspects of these models, an offensive U.S. gun policy would confine handgun ownership to the military and special police forces because more than 87 percent of violent crimes are committed with handguns. Only shotguns and manually loaded rifles would be legal for civilians to own.

In addition, the U.S. government would have an extensive registry of every person in the country who owns a gun. Firearm owners would have to store guns and ammunition in separate locked safes. Self-defense would not be considered a good reason to possess a firearm. Applicants would take written and practical courses followed by exams and pass mental-health and drug screenings — simple measures that we don't currently require. To institute this legislation, the United States would need to organize a countrywide mandatory buyback program like Australia.

As long as guns are in wide circulation, people who intend to harm will get hold of them. In 2004, according to a Justice Department report, among state prison inmates who possessed a gun at the time of offense, 40 percent obtained it from an illegal source and 37 percent obtained it from family or friends, as Adam Lanza did, using his mother's legally purchased guns in the 2012 Sandy Hook Elementary School massacre.

Modest measures won't by themselves stop those who are set on murdering with guns. Civilians who have enough disregard for law and society to orchestrate a mass shooting or fire at their domestic partner won't necessarily get guns through legal means. The most effective solution is to limit the number of firearms available.

While some of these policies might not be popular in the current American political climate, they have all worked in other countries. They could also work here. The choice is ours.

Samantha Paige Rosen is a Philadelphia-born writer and contributor to the Huffington Post and the Week.  samantha@spr-writingresearch.com