There were some noticeable absentees as 100 countries gathered in Oslo this week to sign a treaty banning cluster munitions. While 18 of the 26 Nato countries were on board, the world's superpowers - the US, Russia and China - were all no-shows.
Why does the US, with its long tradition of human rights and international moral leadership, refuse to join this cause? Cluster munitions, after all, are inherently indiscriminate weapons, scattering "bomblets" over wide areas and leaving behind deadly "duds" that act as de facto landmines killing civilians long after war ends.
The US stayed away from Oslo partly because the Pentagon is rather attached to its cluster bombs. During the Vietnam war, the US military dumped thousands of them on Vietnam, Cambodia and Laos. The US also used cluster bombs in Kosovo, Afghanistan and Iraq, dismissing the many civilian casualties as collateral damage.
In the 1970s, the International Committee of the Red Cross, Sweden and several other small countries called for tighter regulation of cluster munitions, horrified by their impact on civilians in southeast Asia. But US "military experts" scoffed at such suggestions and cast aspersions on data, gathered by Sweden, revealing cluster bombs' human impact.
Indeed, the Pentagon has long been loath to give up weapons, even seemingly contemptible ones, if they give US troops the slightest battlefield advantage. Despite considerable international consensus that the military value of landmines is outweighed by their devastating humanitarian effects, the Pentagon continues to assert its prerogative to stockpile and deploy mines.
The Bush administration has reinforced this tendency, given its particular aversion to international constraints on the US military, whether on the treatment of POWs or deployment of anti-ballistic missiles. They often felt multilateral treaties posed a threat to US sovereignty.
For anti-cluster bomb campaigners, the question now is whether the incoming US administration will act differently. Barak Obama won the election claiming he would bring change to Washington. But will he change US cluster munitions policy?
Though Obama is currently non-commital on the cluster munitions ban - a spokesperson said he would "carefully review the new treaty" - he believes in multilateralism and, as a senator, voted for restrictions on US cluster munitions use.
"In general, I strongly support international initiatives to limit harm to civilians caused by conventional weapons," Obama said in September. "As president, I will help lead the way on these issues."
However, with his anti-Iraq war stance, he may be nervous to seem soft on national security, an epithet often leveled at the Democrats. Obama's party has unpleasant memories of Clinton's clashes with the Pentagon over homosexuals in the military and may want to avoid an early battle with the defence establishment.
To overcome resistance to the cluster bomb ban, Obama should argue that signing the treaty would represent a small step toward reinstating US global credibility and good will, following eight years of disregard for humanitarian constraints on war, multilateral institutions and international opinion.
Joining the Cluster Munitions Convention would demonstrate that the US is willing to reassert its international moral leadership and use its immense power with benevolence, magnanimity and restraint. Such symbolic action may be far more potent than any weapon of war.