In Hawaii last week the U.S. Army tested a ground-transport robot that might one day provide intelligence, surveillance, and reconnaissance while easing soldiers' loads in battle.

The U.S. has been ramping up tests of military robots and recently an Army general stated on record that he believes a quarter of U.S. Troops will be replaced by autonomous or remote-controlled machines by 2030.

The American military is hardly alone.

In December, a Russian colonel general told Red Star newspaper that his country's military would be adopting a number of advanced robotic systems in 2016, augmenting the "dozens of land- and sea-based robotic systems as well as hundreds of Unmanned Aerial Vehicle systems" that are currently used by the Russian Armed Forces.

Similarly, an Iranian general predicted that his country would go to war with machine gun- and rocket-mounted robots in the near future. It's not hard to believe. We've seen crude-but-lethal remote control devices used by rebels in the Syrian conflict and by Iraqi militiamen last year.

Clearly robots are the future of combat, and that raises dicey questions. Robotic warfare is a frequent touchstone in the news, where stories usually focus on DARPA's latest tech or wrestle with important questions about the morality of using unmanned and autonomous machines against humans. Eventually, and perhaps sooner than we think, those questions will change. We have war robots, Russia and China have war robots, Iraqi militias have war robots. What happens when everyone has war robots?

Here's one freaky prediction:

U.S. defense strategists and force planners are confronted by a rapidly approaching future in which guided munitions and battle networking technologies have proliferated widely and are employed by both state and non-state actors across the full range of military operations.

That awful-sounding future is brought to you by a report from the Center for New American Security, "20YY: Preparing for War in the Robotic Age." The report continues (emphasis mine):

But the shift to something resembling guided munitions parity is only a predicate challenge to a potentially deeper revolution afoot - a move to an entirely new war-fighting regime in which unmanned and autonomous systems play central roles for the United States, its allies and partners, and its adversaries.

Obviously that's already starting to happen. There have been more than 500 drone strikes in Yemen, Afghanistan, and Pakistan since 2004. And clearly the U.S. isn't the only one hoping to capitalize on the rise of cheap sensors and tiny computers ... ahem, Iraqi militias.

That, according to the report, could lead to an escalation of armed confrontation. Let's trace that logic.

Pretty much since industrialized nations came into existence force planners have sought a strategy of investing in "ever-smaller numbers of exquisite crewed platforms to penetrate an enemy's battle networks." As an example, consider the capabilities of a single modern fighter jet compared to those of a squadron of WWII era planes. Sorry, gramps. The killer jet wins every time. We need fewer of them because each one is so lethal.

But as unmanned systems get cheaper, and because their use doesn't require the same political considerations that sending soldiers into combat does, the Center for New American Security report predicts a shift to "large quantities of low-cost, expendable unmanned systems" that will "overwhelm enemy defense with favorable cost-exchange ratios."

In other words, you don't need a sweet jet when you have a networked swarm of a few hundred autonomous drones doing your bidding.

So what's the problem?

First, the danger of losing soldiers and massively expensive weapons systems has been a valuable regulator in modern armed conflict. Norms of behavior have evolved over decades of military interactions between manned submarines, ships, and aircraft. You don't order an attack on an enemy's manned sub unless you're willing to have your own sub attacked in response. In moments of high tension before war has broken out, those norms have helped maintain stability. Simply put, no one wants to pull the trigger unless they have to. The immediate consequences could be dire.

But with a shift toward autonomous systems that are essentially dispensable, a commander directing a bunch of cheap robots from a remote location might not hesitate before engaging an enemy's robotic forces. At that point you have military engagement, exchange of fire. Diplomacy would be a weak brake in the middle of armed exchanged.

And that's actually the rosy part of the scenario, because it assumes warfare between two nation states, stable actors for whom there exists at least some historical precedent of restraint. But that's not the world we live in. In the U.S. we've been bracing against attack from irregular adversaries since 9/11, and Europe has been deeply rattled by the recent outbreaks of terror there.

And that's the truly scary part of the future of robotic warfare. By and large the technology behind robotic weaponry is being driven by incredible advances in consumer electronics. That's a radical shift -- typically military developments have trickled down to consumer technologies, and not the other way around.

Cheap sensors -- GPS, infrared, LIDAR, stereo vision -- are proliferating, and the tools to make small robots that fly or drive or swim are cheap and accessible. A guy tinkering in his garage with a Raspberry Pi kit probably isn't going to make the next Predator Drone, but the gulf between those extremes is shrinking.

We live in an incredible age of technology and progress. But it would be naive not to look down the road a ways, as public figures like Bill Gates and Elon Musk have done, and see a bleaker future if these issues aren't discussed openly by reasonable people in search of solutions.