There is no job description for what a superpower nation should do. Given the instability and uncertainty in some parts of the world, though, a good starting point would be to use its moral authority to promote peace. That is one of the key assignments of US foreign service diplomats, who serve at more than 265 embassies, consulates and diplomatic missions. Yet their work is seemingly being undermined by their country's overseas weapons sales, which last year totalled a record US$66.3 billion, 78 per cent of the global amount and three times the previous year's figure.

To those advocating an international arms trade treaty to regulate the industry, such sales are nothing short of exporting turmoil. Most of the American exports went to developing countries, primarily in Asia and the Middle East. Of particular concern were agreements with Saudi Arabia, which amounted to more than half of the US figure. The Saudi government has long been accused of human rights violations, particularly against opponents of the autocratic ruling Saud family.

Russia, the main weapons exporter to civil-war-wracked Syria, was second on the list compiled by the US' independent Congressional Research Service, and France third. The report came just weeks after international negotiators failed, after a month of talks at the UN, to agree on a framework for a landmark pact that would regulate trade in conventional arms to stop them "contributing to human suffering". Hours before a deadline, the US said it needed more time to study the draft, unsurprisingly starting an avalanche of excuses from other major weapons-supplying nations. It is to be hoped that the matter will be raised and brought to a vote when the 193-nation UN General Assembly meets later this month.