IF ALL—or even most—countries abided by the letter and spirit of the UN Arms Trade Treaty (ATT), the world might be rather less grim. Governments that sign up are supposed to halt exports of weapons if they have good reason to think they will be used to flout international humanitarian law. That could cover both internal repression and waging wars by inhumane methods.

Every country in the European Union has ratified the treaty; when it was being crafted, Britain was a keen advocate. But Russia and China have stayed out. The American administration (under Barack Obama) inked the accord, but it has yet to be ratified by the Senate and this looks unlikely to happen. The treaty, which covers everything from tanks to small arms, was opposed by America’s gun lobby. Conservative critics in Washington, DC, now call it a piece of liberal Utopianism which would hobble America without reining in its main rivals.

The fear of hobbling may be exaggerated. A year ago, the High Court in London disappointed anti-war campaigners. It ruled that Britain’s deliveries of weaponry to Saudi Arabia were not in violation of the treaty, despite the terrible civilian casualties in Yemen, where a Saudi-led coalition is fighting an Iranian-backed one. NGOs that brought the case have pledged to fight on, and were recently given the right to appeal.

The court ruling focused on a narrow question: whether at the time he gave his approval, the trade minister had reason to think that British-made weapons would be used to perpetrate atrocities. Much of the hearing was conducted in secret. But in their open arguments, lawyers for the government stressed the close relations between British and Saudi militaries, which enabled Britain to have some say in the selection of targets. Whether that improves Britain’s moral standing or makes it seem even worse is, of course, a matter of opinion.

Canada was an unlikely absentee from the accord. But in a careful pronouncement last February, its foreign minister, Chrystia Freeland, promised legislation that would pave the way for her country to join. Critics said there was a loophole. Canadian-made weapons or parts could still be shipped to America and thence who knows where. The bill is still being picked over by parliamentarians in Ottawa.

No Western country wants its weapons used to harm Yemeni civilians, and most democracies crave the respectability that goes with signing up to the ATT. But many balk at breaking ties with the lucrative arms markets of the Gulf.