Drone, the catch-all term for uncrewed flying vehicle, descends from a far more specific bit of jargon, once used exclusively to refer to aerial targets. Few aircraft are built for the express purpose of being destroyed, but targets are, and that more casual attitude toward the destruction of aerial robots has expanded to include the whole category of modern uncrewed apparatus. All of this is to say: through some means, forces on board a U.S. Navy vessel had an interaction with a drone, and likely sent it into the sea.

“At approximately 10 a.m. local time, the amphibious ship USS Boxer was in international waters conducting a planned inbound transit of the Strait of Hormuz,” read the statement from Jonathan Hoffman, the chief Pentagon spokesperson. “A fixed wing unmanned aerial system (UAS) approached [USS] Boxer and closed within a threatening range. The ship took defensive action against the UAS to ensure the safety of the ship and its crew”

The Pentagon’s statement differs in language from the wording used by President Donald Trump, who claimed that “the drone was immediately destroyed” after receiving multiple calls to stand down. According to CNN, U.S. defense officials claim that the drone was disabled not by bullets or missiles (“kinetics,” in the jargon), but rather by jamming.

Specifically, it was almost certainly jamming via MRZR LMADIS, or a Polaris MRZR vehicle sporting a Light Marine Air Defense Integrated System. While a Corps official said as early as May that the deployment of the system to the Middle East was winding down, observers online noted that a MRZR LMADIS system was visible on the deck of the USS Boxer, an amphibious assault ship, for its transit through the Strait of Hormuz — a presence revealed in pictures uploaded earlier that day.

The incident is just 28 days after Iran shot down a Global Hawk over the Strait of Hormuz. While the drone jammed by the Boxer has yet to be identified, Iran has drone bases in the area (which is, again, a narrow body of water that borders Iran, and over one side of which Iran claims sovereignty). Non-state actors have also operated drones in the surrounding area, sometimes supplied by regional powers. The downing of the Global Hawk almost risked escalation, though the uncrewed nature of drones versus the certainty of human casualties in the event of a retaliation appears to have calmed tensions.

Instead, the recent exchange of attacks on drones hearkens back to an earlier era of tension in the Strait, invoking the attacks on commercial vessels during the Iran-Iraq war which ultimately involved US naval patrols and is recorded in history as the Tanker War. Jamming drones, in theory, poses less of a risk to other commercial or otherwise peopled aircraft, but the likely consequence of the exchange of drone destruction in the summer of 2019 is that commercial aircraft will steer clear of the area. After all, the greatest tragedy of the Tanker War involved a U.S. cruiser mistaking a civilian Iranian airliner for an attacking jet fighter, leading to the deaths of 290 people.

It is also worth noting that the immediate answer to a drone threat to ships appears to be simply parking a ground vehicle carrying a counterdrone system on the deck. The counterdrone field is full of possible solutions, but most have focused on either facilities or dismounted patrol protection, looking at handheld devices or larger installations at fixed points at bases. There is likely an underserved market in counterdrone solutions for ships, especially aimed at stopping mid- to low-end fixed-wing craft.