Satellite fallout

The United States launched a missile last week to blast apart an ailing spy satellite and prevent harm from its toxic fuel if the satellite fell to Earth. But did this Star Wars-like feat also have a military purpose? Such a possibility sends a message about weapons in space.

The Pentagon was wisely transparent about this action. It announced its intentions and now says it will share data about the resulting debris. The US also hit its satellite in low orbit, so as to minimize space garbage. And the Defense Department insists its satellite intercept was a one-time event and not the start of an antisatellite program.

And yet no amount of explanation can change the fact that this shoot down has a crossover military benefit. It shows that the US can now fairly easily recalibrate its missile defense system into an antisatellite one. The last time the US shot down a satellite was 22 years ago, when it nailed one with a weapon in a test launch from a fighter jet. This time, the US did it with a missile from a cruiser in the Pacific.

With widespread mistrust of the US, the shoot down is fueling fears of a space arms race.

The US spends more than $12 billion a year to try to intercept incoming missiles from space (think of the recent missile tests by North Korea and Iran). In 2006, it adopted a policy to assert "space control." Last year, China launched an anti-satellite missile that exploded a defunct weather satellite. It did this in secret and left debris in a dangerously high orbit.

Not surprisingly, last week's explosion generated protests from Russia and China, and concern among some arms-control experts that it would encourage antisatellite tests by other countries. (Russia made such tests in the cold war days – as did the US.)

It's time to begin serious negotiations on a new treaty to govern weapons and space. The last one, a United Nations treaty, dates from 1967 and bans weapons of mass destruction from space, but not conventional weapons.

Beijing and Moscow have been pushing a new treaty. Last week they introduced a draft space-weapons ban to the UN Conference on Disarmament. But the US won't negotiate on that draft's proposals. Philosophically, it wants to maintain "freedom of action" in space. But there are also serious problems in defining a space weapon (the Russians say the American space shuttle is a weapon) and with verification because potential space weapons such as launchers have multiple purposes. The US, too, is concerned about giving up its anti-missile program.

Instead of a treaty, it wants confidence-building measures, but the Chinese refuse to talk about these because it wants a treaty.

Treaties aren't perfect. A temporary test ban might be considered for now while the US reconsiders its costly effort to create a system to knock out rogue missiles and also works to build an international consensus against the weaponization of space.

Right now, the US has the most to lose from a space arms race because it has the most satellites. Yet China and Russia feel vulnerable because the US is ahead in potential weaponry.

All sides, then, have an incentive to talk. And at this stage, let's do at least that.