It is arguably the oldest and simplest battlefield tactic out there: swarming, the attempt – usually by a side richer in numbers than firepower – to overwhelm the opposition not necessarily by precision or force, but by sheer numbers.

In centuries gone by, those numbers might have comprised surging ground troops or volleys of ammunition. But today, as with so many aspects of modern warfare, the task can be done by drones. Dozens, or perhaps even hundreds or thousands, of cheap, devastating drones.

The Telegraph London