When satellites collide in space, should ordinary people be worried? Here’s a scenario for global doom that should have your hair standing on end.

News reports on February 12 that two satellites had collided some 491 miles above the Earth were compelling. There was a whiff of Cold War intrigue about them. A defunct Russian communications relay satellite and an American commercial satellite had met abruptly in space with a closing speed of more than 22,000 miles per hour. They were shattered into many hundreds of pieces, creating an ever expanding debris cloud. In turn, that cloud threatened the satellites of other countries in similar orbits.

And yet, no one was harmed. Space is a big place, isn’t it? The reports noted that there were already thousands of pieces of space junk large enough to be tracked and catalogued. Nonetheless, no one has ever been harmed by a bit of space garbage.

At the moment, the amount of debris in “low-earth orbit”—the region of space that extends a few hundred miles above the atmosphere—is merely a nuisance. The United States tracks objects in space and shares the data with the world. Satellite handlers based in many countries use the data to slightly alter the course of their birds if a collision seems possible.

End of story? Not quite. “Orbital space” is a natural resource, as surely as land, air, and water. It must be protected because it is home to nearly a thousand satellites put up by many countries—communications, geo-observation, geopositioning, weather, and other kinds of satellites. “Globalization” would not be possible without commercial satellites.

Further, the United States’ military-related birds permit the country to conduct “precision” war. For the first time in history, satellites provide the data and the guidance necessary to enable bombs and missiles to actually hit the targets they are fired at. That’s a moral plus. If a war must be fought, it should be prosecuted in such a way that military targets are hit and civilians spared to the greatest extent possible. No other country can fight a conventional war as cleanly and humanely as the United States. Satellites make the difference.

Because of the importance of satellites to the American way of war, the United States insists that it must achieve the capability to militarily dominate space in a time of conflict. It is the only country that claims that right. Space, says international law on the other hand, is the common heritage of humankind and must be devoted to “peaceful purposes.”

America’s truculent space-dominance language annoys many of its friends and allies. Meanwhile, some major powers—particularly China and Russia—think it smells of imperialism. A country that could control space in a time of conflict might also exercise that control in a time of peace.

Since 1981, virtually every country save the United States and Israel has gone on record in the United Nations General Assembly as favoring a treaty that would prevent an arms race in space. Every year, the United States—under presidents Ronald Reagan, George H.W. Bush, Bill Clinton, and George W. Bush—has used its veto power at the Conference on Disarmament in Geneva to prevent serious talks.

No one, including the United States, is likely to have actual weapons in space in the foreseeable future. Space control does not require such weapons. Ground-based, sea-based, and even air-based antisatellite weapons (ASATs) can do the trick. The United States has long been working on a variety of highly sophisticated ASAT programs—indeed, the infrastructure for missile defense is the sort of infrastructure needed for ASAT systems.

When a country builds ever greater military capabilities, potential rivals react. China, in particular, is wary of the coercive possibilities of U.S. military power. The Middle Kingdom says it wants a space treaty, but in January 2007, it tested its own somewhat primitive ASAT—a kinetic-kill device that roughly replicated a test the United States carried out in 1985.

Is a space-related arms race under way? Yes. But there is still time to ratchet it down, and the Obama administration has signaled that it might do so. That will be difficult, though. Exceptionalism is a major driver of foreign policy, and influential people and hard-line think tanks are comfortable with the idea that full-spectrum dominance in all things military is America’s right.

A nightmare scenario: The United States continues to work on its “defensive” ASAT systems. China and Russia do the same to counter U.S. capabilities. India and Japan put together their own individual systems. Ditto for Pakistan, if it survives as a coherent country. Israel follows suit, as does Iran.

In a time of high tension, someone preemptively smashes spy satellites in low-earth orbits, creating tens of thousands of metal chunks and shards. Debris-tracking systems are overwhelmed, and low-earth orbits become so cluttered with metal that new satellites cannot be safely launched. Satellites already in orbit die of old age or are killed by debris strikes.

The global economy, which is greatly dependent on a variety of assets in space, collapses. The countries of the world head back to a 1950s-style way of life, but there are billions more people on the planet than in the 50s. That’s a recipe for malnutrition, starvation, and wars for resources.

The United States, by far the world’s most-advanced space power, must take the lead in Geneva and engage in good-faith talks. If not, the space-is-ruined scenario could become reality.