New naval anti-piracy tactics – pepper spray and “domestic” riot control

[Cross-posted from The Trench]

Yesterday the Smithsonian “Smartnews” site featured the article Robot Ships And Pepper Spray—the Latest in Pirate-Fighting Tech. According to the piece, UK researchers are actively looking into mobilising capsaicin – the active ingredient in pepper spray – to fend off pirate attacks at sea:


The age of naval battles between huge ships on the high seas seems to have passed into distant memory. Instead, some of the most devastating attacks on giant vessels in recent years have been executed by boats small enough to get through the larger ships’ defenses.

But now, governments around the world are working on technology designed to stop these attacks. In the U.K, researchers are working on a remote monitoring system—called the MATRiX system—that resituates the traditional responsibilities of a lookout to land-bound control rooms. The system has a connected network of anti-pirate deterrents attached to the outside of the ship. If a threat is detected, the deterrant [sic] system releases two relatively simple tools—nets that will catch in the propellers of attacking boats and a fog of capsaicin, the active ingredient in pepper spray (and bear repellent).


My question is: how does that fit with international law?

It stretches the understanding of non-prohibited purposes as defined in Article II, §9(d) of the Chemical Weapons Convention (CWC), which allows the use of riot control agents for law enforcement purposes, including domestic riot control. The concept of “law enforcement” is vague in the CWC and efforts are underway to clarify the notion in the context of various research and development activities concerning incapacitants.

In this particular case, however, it seems that not even law enforcement officials would  the responsible for the decision to release the capsaicin against pirates (unless they are the ones sitting in “land-bound control rooms”). The afore-mentioned article suggests that the device would be deployed by the  merchant ship under attack. Even if law enforcement officials would be at some land-based centre, would they be able to override the captain’s authority or would they just give the captain the green light to activate the system when needed? If the captain must call in authorisation from land, what country’s jurisdiction would come into play? The country under whose flag the ship is sailing? The country on whose territory the control rooms are located? The country whose nationality the law enforcement officials possess?

In light of the ongoing privatisation of security (who actually uses force to defend the ships against attacks? who sits in the land-based control rooms?), the blurring of boundaries between armed conflict and counter-terrorism / -crime operations, and the banalisation of riot control agents, it would appear that legal clarity about this new contraption should be established by the relevant national authorities and the international community (represented by the Organisation for the Prohibition of Chemical Weapons—OPCW).

Having said that, capsaicin is a toxin—a poison produced by a living organism. As such the legitimacy of its application is also covered by the Biological and Toxin Weapons Convention (BTWC). That treaty does not distinguish between whether the compound was derived from the chili pepper or produced synthetically. More importantly, however, the BTWC does not make an exception for law enforcement purposes. This leaves the question as to whether “law enforcement” can be considered to be one of the “other peaceful purposes” in Article I.

As it stands now, nobody has really been able to give me a sound explanation why the provisions of the CWC should supersede those of the BTWC.

I am open to good legal arguments.