An undated image released by Defense Distributed shows the parts of the “Liberator,” which is being touted as the world’s first 3-D printable handgun. (Defense Distributed via EPA)

Once again, with mass shootings in a church in Charleston, S.C., and a movie theater in Lafayette, La., Americans are discussing gun control — or discussing why we are not discussing it. With so many mass shootings and so little action, President Obama recently called gun-law reform the policy area in which he has “been the most frustrated and the most stymied.”

But technology is a bigger obstacle to reducing future gun deaths than either the National Rifle Association or differing interpretations of the Second Amendment. Within a few years, the greatest challenge to the government’s ability to control firearms will be advances in additive manufacturing, popularly known as “3-D printing.”

The ability to “print” or manufacture guns privately will allow individuals to bypass background checks, the primary way that guns are regulated today. And that challenge will expand exponentially as the technology advances, one day enabling individuals to print chemical, biological and nuclear weapons of mass destruction at home.

How do you run background checks on someone who can print a gun at home?

Today, licensed firearms dealers are responsible for conducting background checks and ensuring that they sell only to people legally eligible to purchase. That’s part of the reason that Obama’s 2013 gun-control proposals included not only more restrictions on who is permitted to buy and own guns, but also called for private sellers — who today don’t have to run background checks — to sell instead through licensed dealers.

That’s not possible when individuals can print their own weapons at home. With no seller, who runs background checks or denies purchase? The government’s control mechanisms fall apart.

This is not a futuristic speculation; 3-D printed handguns are already on the street. The government is struggling to respond to these guns, which are hard to detect and deadly.

Oddly enough, the State Department has made one effort at regulating whether these weapons will be available within the United States. The State Department has asked a Texas-based organization called Defense Distributed to remove from public access the blueprints for its 3-D printed “Liberator” handgun and other related files, arguing that making these available outside of the country may violate International Traffic in Arms Regulations. Defense Distributed is challenging these proposed restrictions on the grounds that they violate the First and Second amendments.

Next up, weapons of mass destruction: How do you control their spread if they can be privately printed?

The threat of privately printed weapons will soon grow beyond the lethal handguns now in circulation. As we argue in research forthcoming in the October issue of the Journal of Policing, Intelligence and Counter Terrorism, considering expected advances in the technologies, terrorist groups will threaten nations with 3-D printed chemical, biological and nuclear weapons within a couple of decades.

Consider two facts. First, terrorists are now more willing to utilize WMD than before. Bruce Hoffman has argued that while at one point the conventional wisdom was that terrorist groups had no desire to inflict mass casualties, the 9/11 attacks and the rise in religiously motivated terrorism showed that this logic no longer holds.

Second, the opportunity to use WMD will expand as 3-D printing makes these weapons more available. In the past, only countries could reliably manufacture WMDs, given the formidable technical and economic investments involved. Accordingly, as Albert Mauroni has written, most major anti-proliferation measures and agreements have focused on preventing states from transferring WMD technology to non-state groups. The few instances in which non-state groups have successfully produced and used WMDs, such as the 1994 and 1995 Aum Shinrikyo attacks, have shown that “the technical difficulties of achieving such an attack are considerable,” as scholars such as Gavin Cameron argue.

That barrier will fall when 3-D printers can manufacture these weapons. Private groups will be able to bypass international controls on weapons production and proliferation — in much the same way that individuals producing handguns at home can bypass point-of-sale firearms controls.

When should we expect to see WMDs that can be printed at home? 

When will 3-D printing become advanced enough to produce WMDs? Though it sounds like science fiction, the best projections suggest that it will happen within a few decades. The technology to print from standard metals such as steel and titanium already exists, allowing for firearms far stronger than the roughly made and fragile plastic handgun. Progress in mixed-materials printing, which can currently use 14 materials in the same printer, is being made both in the laboratory and among hobbyists. Work in biological materials is expanding at a rapid pace, with scientists printing human organs, medications and even hamburgers; bacteria and chemicals aren’t far behind. Production is also moving beyond simple items, allowing for the fabrication of increasingly complex objects.

As an example, SpaceX is utilizing innovative 3-D printing techniques to manufacture components for its spacecraft and rocket engines. It should also be possible to use 3-D printers to print components needed to produce nuclear weapons, potentially even from fissile materials such as uranium or plutonium.

Most interestingly, laboratories have already printed at the molecular level. Such printing will probably migrate out of the lab within 20 to 30 years.

What is to be done?

Governments should begin thinking now about how to expand 3-D printing’s tremendously useful potential to improve lives — while simultaneously countering its potential for mass destruction.

Concerns include possible civil liberties infringements — such as those at the heart of Defense Distributed’s lawsuit — and technological advances that outpace the government’s ability to respond. 3-D printing promises to be the largest change in production methods since the Industrial Revolution. Let’s be ready for the dangers.

Daniel C. Tirone is an assistant professor of political science at Louisiana State University. James Gilley is a PhD candidate in political science at Louisiana State University.

This post has been updated for great technical clarity.