The backlash against US President Joe Biden’s decision to transfer cluster munitions to Ukraine grows daily – and rightly so. Leaders and officials from the UK, Canada, New Zealand and Spain all swiftly said they were opposed to the use of the weapons. That wasn’t surprising, since 123 states around the world are committed to the goals of the Convention on Cluster Munitions, which entered into force in 2010 and prohibits all use, production, transfer and stockpiling of the bombs. Given that a White House spokesman had previously said that if Russia used them it would “potentially be a war crime”, and now the same administration is going to provide Ukraine with those very munitions, it would be easy to see this as just one more nail in the coffin of the “rules-based international order” that the US and its allies constantly claim to be promoting. That appeared to be the concern of Democrats such as Congresswoman Barbara Lee when she and 18 other Democrats issued a statement saying that the announcement “runs counter to Congress’s restrictions on the transfer of these weapons and severely undermines our moral leadership.” And yet there’s something about these weapons that causes a unique revulsion. People in many countries, but especially two in South-East Asia, know why. It’s not just that when not lethal these bombs, which split into tiny bomblets, indiscriminately maim anyone in their path, and it is near-impossible to claim they will not harm civilians – which they have done in the hundreds of thousands over the years. A serious percentage of them don’t go off and can lie like hidden landmines for decades. Children pick them up, thinking they are toys. Farmers unwittingly tread on them in fields. This was what Cambodia’s Prime Minister Hun Sen was alluding to when he stated on Sunday that his country “has suffered painful experience from cluster bombs dropped by the United States in the early 1970s. Until now, it has been more than half a century, but we have not found a way to destroy all of them yet. It will be the worst danger for the Ukrainians for decades or even centuries if those cluster bombs are used.” The Laotian Ministry of Foreign Affairs added on Monday: “The Lao people were victimised by this deadly cluster munition more than five decades ago and even today they continue to be affected by the unexploded ordnance as it continues to pose serious threats to the lives and livelihood of our people.” No one in the world should be victimised by such “heinous” weapons, it said. For context, in the Vietnam War, between 1964 and 1973, the US military dropped more than 270 million bombs on Laos and, in almost the same time frame, 26 million on Cambodia. The US may have contributed hundreds of millions of dollars to pay for ordnance to be destroyed in those countries, but they are still all over the place. Two years ago, for instance, a 2000-pound bomb was found in the river near the Royal Palace in Cambodia’s capital, Phnom Penh. The issue was already on my mind, as we are going on a family visit to Angkor Wat, the country’s stunning temple complex that dates back to the 12th century, next month; and I knew I must drill into my boys that on no account are they to stray from the official paths. Because for those not wary enough, or simply unlucky, the consequences can be devastating. A farmer named Yan Sam En found four cluster bombs in the forest near his home in north-east Cambodia 20 years ago. “I didn't want my children to play with the bombs, so I collected them, and as I did, one exploded. It blew off both my arms, and left me totally blind,” he told China’s Xinhua news agency. “Time has not healed me. The US deprived me of everything. In a few seconds, I went from breadwinner to useless person.” Far too many in Middle Eastern countries have similarly heart-rending tales to tell. Mr Biden’s explanation that “the Ukrainians are running out of ammunition” doesn’t hold water – unless using mustard gas, biological warfare or other weaponry previously considered too barbaric to deploy is also now on the table. Neither is the fact that both Russia and Ukraine have already launched cluster munitions any excuse. There is a reason why the majority of the world’s states have banned them. If Mr Biden won’t listen to Cambodia’s Hun Sen or Laos’s Foreign Ministry, let’s hope he may take heed of members of his party, or of Republican Representative Matt Gaetz, who is co-sponsoring an amendment to try to stop the transfer. “These cluster bombs will not end the war in Ukraine and will not build a more stable country,” Mr Gaetz wrote in a tweet. “Children will be left without limbs and without parents because of this decision.” Mr Biden has invoked a special legal provision that allows him to bypass arms export restrictions “if he deems the aid to be a vital national security interest”, according to <i>The New York Times </i>editorial board. But in no way can sending these morally repugnant munitions to Ukraine be considered a “vital national security interest” of the US, which is not at war with Russia, and has no defence treaty with Ukraine. No, Mr Biden is crossing what most of the world considers to be a red line. If he thinks that in this case “the ends justify the means”, he should be prepared to explain why to the families of the innocents who will die or be disfigured by the bombs he should be destroying, not sending abroad to wreak their terrible work.