Reverse engineering airplane replacement parts is a tricky task, especially when the parts themselves are in short supply and the cost of error is a plane crashing. This is part of what makes sanctions on airplanes, and repair parts, so damaging: there just aren’t that many ways around not having the right parts. Or at least, there weren’t, but 3D printing changes that whole picture.

A new RAND study on the way additive manufacturing, better known as 3D printing, could create new security threats details everything from printed grenades to lost job security. Nested in the report is one risk with a more immediate impact: 3D printing as a way for nations to get around the ramifications of sanctions.

Take, for example, the case of commercial aircraft in Iran. As part of the Joint Comprehensive Plan of Action, or the Iran Deal, the United States agreed to lift sanctions on commercial aircraft and aircraft parts. With sanctions lifted, the Iran was set to buy or lease almost 120 new Boeing aircraft, which the airline boasted as a move that would finally bring the average age of planes in its fleet down below 20 years. With the Trump administration withdrawing from the deal, those plane orders are unlikely to go through, and the airline will have to rely on an aging fleet of craft, with whatever spare parts it has on hand to keep them in the air.

By the middle of this century, 3D printing could make nations like Iran self-sufficient when it comes to maintaining fleets of foreign-built aircraft. From RAND:

[The] 2015 Joint Comprehensive Plan of Action nuclear agreement between the United States and Iran specified various forms of sanctions relief for Iran. The January 2017 delivery of an Airbus A321 was particularly noteworthy: It was Iran’s first new Western-made aircraft in several decades, representing a new day for a domestic airline that had become infamous for its crashes as the aging fleet struggled to fly using only “smuggled or improvised parts.” In the future, such challenges could be overcome more easily using [additive manufacturing]. And while [additive manufacturing] might reduce the number of accidents, that benefit comes at the cost of weakening the effectiveness of sanctions, which represent a basic tool for managing geopolitical challenges.

For sanctioned nations (and, in this case, the passengers on airlines operated by those nations), 3D printing can be a lifesaving tool. In so doing, it absolutely undermines the coercive power of sanctions regimes.

Files for parts are much easier to transmit across borders and around controls than parts or part-making equipment itself. And while smuggling industrial plans is as old as the industrial revolution itself, export controls on intellectual property and industrial design are in place to make it extremely difficult. Tools like 3D printing undercut that power, using the interconnectedness of the web as a route around 20th century controls.

“With access to printers, raw materials and designs,” the RAND paper continues, “a state could more easily weather the hardship of such restrictions.”