But the devices bring other dangers. A smattering of these lethal bomblets can lie unexploded long after a battle for civilians to trip over or curious children to pick up.

That's just what 9-year-old Saleh Khalaf did when he saw a bright yellow orb along a roadside in Iraq in 2003. Moments later, he lost an eye and both hands when the cluster bomb detonated. His recovery, after intense medical treatment in an East Bay hospital, was detailed in a Chronicle series that won a Pulitzer Prize for photography four years ago.

The lingering horrors of these munitions led 111 nations to ban cluster bombs in a treaty reached in Ireland on Friday. Wars in places such as Iraq, Somalia, Laos, Lebanon and Bosnia made the point that the bomblets can't be ignored or justified. That may sound courageous: a worldwide consensus to eliminate an indiscriminate weapon blamed for killing noncombatants in a dozen countries.

But this agreement could be nothing more than a hollow, feel-good moment. That's because the world's biggest militaries, including the United States, won't sign. The primary argument, it seems, is that cluster bombs are just too good to give up.

Fortunately, there's an opportunity for shame and stigma to change things. In the final hours of treaty talks, British Prime Minister Gordon Brown broke ranks with Washington and agreed to the ban. Over the next eight years, his country and the other signatory nations will eliminate cluster munitions and clean up battlefields where their forces used them.

Emptying Britain's armory is one thing. Exerting international pressure is another: Brown's action should lead the holdout nations to reconsider their position. Along with the United States, this Hall of Shame includes China, Russia, Israel, India, Pakistan and Brazil. Each is either armed to the teeth or an active military supplier. Weapons experts estimate that the largest of these armies each has up to a billion baseball-size bomblets.

If these countries, especially the United States, won't join the ban, then their leaders should set specific ground rules for their use and promise to rid the terrain of unexploded munitions when the fighting stops. Sens. Patrick Leahy, D-Vt., and Dianne Feinstein, D-Calif., have authored a proviso in a spending bill signed by the president stating that cluster munitions can't be sold to allies unless the weapons have a failure rate no greater than 1 percent and will only be used against defined military targets. It won't prevent the United States from using the weaponry, but it should curb an infamous "Made in the USA" export.

The Bush administration, which badly needs a lift in its global image, should rethink its refusal to sign this humane agreement. The treaty, let it be known, has loopholes that should satisfy even the most hawkish White House warrior.

For example, an earlier draft was softened to allow cluster-bomb-using armies to operate in alliances with nations banning the devices, a change that avoids problems within NATO. Also, the Pentagon is readying a new generation of "smart" cluster bombs that can be more precisely targeted and even ordered to self-destruct if they go astray. These newer models wouldn't be banned by this week's treaty.

It's time to discard a crude weapon that an overwhelming number of nations don't want. Sign the ban on cluster bombs, Mr. President.

This article appeared on page G - 10 of the San Francisco Chronicle