The world's most worrisome military flash point is arguably not in the Taiwan Strait, the Korean peninsula, Iran, Israel, Kashmir or Ukraine. In fact, it cannot be located on any globe. The contested territory? The no-man's-land of Earth's orbit, where a conflict is unfolding that is an arms race in all but name.

About 1,300 active satellites now reside in the region of outer space immediately surrounding our planet, where they provide worldwide communications, GPS navigation, weather forecasting, and more. For nations that rely on a select number of those satellites for modern warfare, space has become the ultimate high ground, with the U.S. as the undisputed king of the hill. Now, as China and Russia aggressively seek to challenge our superiority in space with ambitious defense and exploration programs of their own, this power struggle risks sparking a conflict that could cripple the entire planet's space-based infrastructure. And though it may begin up high, such a conflict could easily ignite full-blown war on the surface of Earth.

Testifying before Congress earlier this year, director of national intelligence James Clapper echoed the concerns held by many senior government officials about the growing threat, saying that China and Russia are both developing capabilities to sabotage crucial U.S. military satellites. China in particular, Clapper said, has demonstrated “the need to interfere with, damage and destroy” U.S. satellites, referring to a series of Chinese antisatellite-missile tests that began in 2007.

The latest Chinese test took place on July 23 of last year and involved, like all its predecessors, the launch of a missile that could be used as a “kinetic weapon” to hit and destroy satellites. Chinese officials insist the tests are peaceful in their purposes and only meant for missile defense and scientific experimentation, but outside experts are skeptical. One test in May 2013 especially sent shock waves through the U.S. intelligence community. That maneuver sent a threatening missile soaring as high as 30,000 kilometers above Earth, approaching the lofty realm of geosynchronous orbit, where satellites move at the same speed as the turning Earth below and thus stay perched over one position on the globe. Those orbits are home to strategic U.S. satellites, including ones that watch for the launch of nuclear missiles, as well as many commercial communications satellites.

The U.S., too, has been active. Shortly after China's 2013 test, the U.S. declassified details of its covert Geosynchronous Space Situational Awareness Program (GSSAP), a planned set of four satellites capable of monitoring Earth's high orbits and even rendezvousing with other satellites to inspect them up close. The first two GSSAP spacecraft were launched into orbit in July 2014. “This used to be a black program—something that didn't even officially exist,” says Brian Weeden, a security analyst and former U.S. Air Force officer who studied and helped to publicize the Chinese test. “It was declassified to basically send a message saying, ‘Hey, if you're doing something funky in and around the geosynchronous belt, we're going to see.’”

Meanwhile the Obama administration has budgeted at least $5 billion to be spent over the next five years to enhance both the defensive and the offensive capabilities of the U.S. military space program. An enemy could provocatively blow up our satellites with missiles, but officials and technology also must prepare for more subtle and devious disabling tactics that appear innocuous at first glance. A spacecraft could simply approach a satellite and spray paint over its optics, manually snap off its communications antennas or destabilize its orbit.

Lasers, too, could be used to temporarily cripple or permanently damage a satellite's components, particularly its delicate sensors. And radio or microwaves could jam or hijack transmissions to or from ground controllers. U.S. defense leaders want to be ready for anything.

Aside from its militaristic initiatives, the U.S. also aims to deescalate the problem through diplomacy, although efforts so far have floundered; in late July at the United Nations, long-awaited discussions stalled entirely on a European Union–drafted code of conduct for spacefaring nations because of opposition from Russia, China and several other countries, including Brazil, India, South Africa and Iran. The failure placed diplomatic solutions for the growing threat in limbo, quite likely leading to years of further debate within the U.N.'s General Assembly.

In the end, debris from a downed satellite—not an initial attack—could be the largest threat to Earth's delicate orbital infrastructure. Satellites race through space at speeds of thousands of kilometers per hour, so even the impact of an object as small as a marble could disable or entirely destroy a billion-dollar spacecraft. And such a destructive collision would itself generate even more threatening shrapnel, potentially creating a cascade of debris that could transform Earth orbit into a demolition derby for centuries.

Without rigorous international accountability and oversight, the risk of accidental collisions and debris strikes will continue to grow as more nations launch and operate more satellites. And as the chance of accidents increases, so, too, does the possibility of their misinterpretation as deliberate, hostile actions in the high-tension, cloak-and-dagger military struggle in space.