The United States has another Valentine's Day Massacre to add to its history.

On Feb. 14, 1929, seven members of Chicago's North Side Gang were killed by members of Al Capone's organization using Thompson submachine guns as part of an ongoing battle to control the illegal alcohol trade in Prohibition-era Chicago.

This week, on Feb. 14, 2018, one man, 19-year-old Nikolas Cruz, shot and killed 17 victims at Marjory Stoneman Douglas High School in Parkland, Fla., using a variant of the AR-15 semiautomatic rifle.

School shootings in America are now commonplace and mark us as the outlier in the developed world. Whereas Canada had zero school shootings last year, and Australia has not had one since 2014, the U.S. has had at least half a dozen so far this year and it is not even March.

What also marks us as the outlier in the developed world is the access citizens have to weapons such as the AR-15 — or military-style weapons. It was this weapon, supplemented with an attachment called a bump stock, that allowed Stephen Paddock to kill 59 people last October from his hotel suite in Las Vegas. It was this weapon that allowed Omar Mateen to kill 49 people at the Orlando nightclub Pulse in June 2016.

AR-15s are not banned as fully automatic weapons, but their killing power is comparable. For this reason, many countries make it difficult for a private citizen to own one. According to the Royal Canadian Mounted Police, in 2007 there were fewer than 4,000 AR-15-type weapons registered in the whole country. In 2013, the National Shooting Sports Foundation estimated that there were between 5 million and 9 million such weapons in circulation in the U.S.

It is time to recognize these weapons for what they are — personal weapons of mass destruction. And that society has a right, even a duty, to act. Some may protest that our hands are tied — that the Second Amendment to the Constitution prohibits us from regulating these weapons even if we wanted to. But that is simply not true. In fact, we already have regulated such weapons. Furthermore, the term "well-regulated" is in the actual language of the Second Amendment.

Let us begin with fully automatic weapons. Since the Firearm Owners' Protection Act of 1986, it has been very difficult to obtain a fully automatic weapon, and no fully automatic weapons intended for civilian use are currently being produced. (Fully automatic means the weapon will keep firing while the trigger is being held down). You cannot argue that automatic weapons are more deadly than current varieties based on casualties they have produced historically.

As mentioned, the St. Valentine's Day massacre of 1929 killed seven people with Thompson submachine guns (aka "Chicago Typewriters"). But there are other examples where the death tolls were not far different. For example, in 1945, Pvt. Clarence Bertucci used a Browning machine gun to kill nine German prisoners of war and wound 20 others in Salina, Utah, in what came to be known as the worst POW camp massacre in U.S. history.

These are just fractions of the deaths today's semiautomatic rifles can cause. Shall we make fully automatic weapons legal?

We also agree that it is unsafe for individuals, or even countries, to have chemical weapons. Since the 1993 Chemical Weapons Convention, the production, stockpiling and use of chemical weapons has been outlawed by 192 participating nations. Can you imagine what kind of carnage might happen if individuals had access to such agents? We don't have to imagine. On March 20, 1995, members of the doomsday cult Aum Shinrikyo released multiple vials of sarin gas into the Tokyo subway. Sarin is an extremely potent nerve agent that causes muscles to spasm, including the muscles for breathing, leading to suffocation and death. It was the deadliest attack to occur on Japanese soil since World War II. Do you know how many died? Twelve — just a fourth of the number killed by Mateen in Orlando and a fifth of those killed by Paddock in Las Vegas.

Finally, we agree that we can infringe on your right to bear arms in other situations where one could threaten dozens. For example, you are not allowed to bring a firearm onto any commercial aircraft, including the small regional jets such as the CRJ700, which seats 63 to 78 passengers. Again, this would potentially represent a comparable death toll to Orlando or Las Vegas.

I do not pretend that much stricter access to such weapons is the only answer to the problem of gun violence in America. After all, the majority of killings are committed with handguns, not assault rifles. But we need to start somewhere. No country that severely restricts access to such weapons has less freedom or more violence than we do. But what those countries do have is something we all want and deserve — a safe place for our children to grow and learn. We all deserve to have that peace.

Chris Johnson is a Twin Cities physician.