THE REVOLUTION in unmanned aircraft is overrated. Five reasons:

First, unmanned aircraft typically lack defensive weapons with which to protect themselves.

Second, unmanned aircraft are relatively fragile.

Third, unmanned aircraft aren’t really robotic in the sense of functioning autonomously.

Fourth, there is little likelihood that emerging technologies will enable unmanned aircraft to become autonomously capable and survivable in the near future.

Fifth, unmanned aircraft are not cheap — at least, not the high-end vehicles for which proponents harbor the most ambitious hopes.

Finally, pilots are still cheaper to produce.