As far as nano-UAVs, there are a growing number of products in the marketplace for the Marine Corps to choose from, said Phil Finnegan, an analyst with the Teal Group.

A Norwegian company, ProxDynamics, is offering a palm-sized miniature helicopter, the PD-100 T Black Hornet, which can fly with an electro-optical camera and thermal sensor provided by FLIR Systems Inc. for night operations. U.K. forces, and possibly U.S. Special Operations Command, have purchased some of the mini-copters, Finnegan said.

Nano-UAVs "definitely [are] a rapidly growing market. That being said, the [contract] value is nowhere near those of the larger systems," he added.

"It tests the waters and provides some understanding of these systems. Also, from a political standpoint, it helps address some of the concerns in Congress about the ability of U.S. companies to really address this market," said Philip Finnegan, director of corporate analysis at the Teal Group, a leading aerospace and defense market analysis company. "It's a way of providing an interim step before you go out and do the final rule. And the final rule is going to take a long time."

One of the most troublesome issues the FAA must address in its final rule is to outline the differences between using a drone for commercial purposes versus solely for recreation, and then to police drone operators accordingly.

Under current law, for instance, it is technically legal to equip a drone with a camera and snap pictures of a scenic countryside. Selling those pictures, however, is not allowed.

Ironically, that system may have created a situation in which the most responsible operators can't use drones legally while the most irresponsible can.

"It's going to be very difficult for the FAA to control this. Part of the problem is there are severe restrictions on the commercial operation of these, and a lot of those people would be the most responsible," Mr. Finnegan said. "When it comes to hobbyists — no training, dim awareness of the risks — there is very little in terms of limitations. It's a serious, serious problem."

As military strategists look ahead, the days of asymmetric warfare and the uncontested airspace that comes with it seem to be drawing to a close. "There are no active area defenses run by insurgents in Afghanistan and Iraq or, for that matter, Syria," says defense analyst Phil Finnegan, of the Fairfax, Virginia–based Teal Group. "But the next generation of UAVs will have to confront potential threats like China. They'll need to be much more capable—faster, with greater autonomy in case communication links are disrupted, and stealthier so they are more difficult for an adversary to detect."

Research firm Teal Group estimates that global annual spending on drones will nearly double from $6.4 billion to $11.5 billion over the next 10 years. Teal's study shows that military drones currently account for 89% of the market, while civil drones account for the remaining 11%. Yet that split is expected to be 86% military versus 14% civil over the next decade.

Phil Finnegan, a drone expert at the Virginia-based Teal Group, also predicted new jobs on the horizon. "There definitely will be growth of new jobs in the UAS industry as commercial operations begin," he said. "At this point, what everyone is waiting for is the FAA to take steps to begin to open air space and that's going to take time."