If ‘Harry Potter’ taught us anything, it’s that invisibility cloaks can open many doors for magic school mischief and dark lord slaying. Outside of the fantasy world of books, however, such technology could violate the Geneva Conventions.

Military ‘invisibility cloaks’ are less literal than those featured in books. These ‘cloaks’ actually refer to reflective surfaces that manipulate light waves in order to conceal a military vehicle from the naked eye and digital radar. These surfaces are easy to apply to guns, tanks, jeeps, ships and jets–which is exactly the problem.

See invisibility cloaks in action!

https://www.youtube.com/watch?v=kxC3ecGVIgo

According to Article 37 of the Geneva Conventions, “Prohibition of Perfidy,” it is illegal for any state military to impersonate civilian vehicles because doing so will just put real civilian vehicles in danger. Likewise, troops can’t dress up as civilians either.

However, camouflage that blends a military vehicle into the environment is legal.

The U.S. military is eagerly researching invisibility cloaks and all of their possibilities, but Royal Air Force veteran and military lawyer Bill Boothby thinks it should tread carefully.

“Conventional camouflage aimed, for example, at causing the enemy to blend into the background, is lawful and bending light might be regarded simply as a technologically sophisticated way of achieving that outcome,” Boothby explained to The Guardian. 

But making weapons or vehicles invisible might complicate things. A soldier carrying an invisible gun could be misconstrued as a civilian.

Amnesty International and other nonprofits have called for a ban of invisibility tech, but Boothby doesn’t think that is necessary.

“An outright ban of autonomy in weapon systems is premature and inappropriate, difficult to enforce and perhaps easy to circumvent,” Boothby said. “Existing law should be applied to this as to any other technology in warfare.”