alt Hacker NewsYes, but while the moat surrounding the US embassy in London will not deter drones, it will prevent any car from reaching the proximity of the building.
A car can carry a much higher explosive load than even a lot of cheap drones. Moreover, in London a car will become suspicious only when it is already close to the embassy, and there is little time available to react, but drones should be detected much earlier.
"drones should be detected much earlier"
Not if you follow in the steps of Ukrainian "Operation Spider Web", which concealed the explosive drones into a double roof of a truck and when the truck got into the proximity of the target, the roof opened and everything flew out at once.
Granted, in the case of an embassy in London, you probably couldn't get a semi there, maximally a modest truck, but that should be enough for some damage.