There is no discreet and low-key way of sending the Patriot antimissile system to another country, but Joe Biden is nothing if not a trier. The US president has left it to unnamed officials in his administration to confirm that Saudi Arabia has taken receipt of these monstrous, truck-mounted interceptors. You can quite understand the sheepishness. In 2019, he promised to make the journalist-killing kingdom a “pariah”. Just this month, he framed the modern world as a “battle between democracies and autocracies”.

What is glaring here is not Biden’s failure to live up to his ideals. It is the untenability of the ideals. Even when the US had a nuclear monopoly and a vast share of world economic output, it had to cut moral corners to fight communism in the nascent cold war. It only went so far in de-Nazifying postwar Germany, for instance. It sponsored the monarchist forces in the Greek civil war. It connived in autocratic rule in South Korea and Latin America. As a less dominant power than it was in the mid-20th century, it would be an odd time for the US to develop a new choosiness about its allies.

Biden can lead the US to success in the present crisis, if he is clear about its parameters. The enemy is not an abstraction called “autocracy”. It is a specific aggressor in a defined territorial conflict. Inducing a change in its behaviour might be possible, but it is likely to require the co-operation of the oil-rich Saudis, the strategically located Turkey and a Chinese state that has the wherewithal to cushion Russia against sanctions. That none of these countries are liberal democracies doesn’t reduce their circumstantial usefulness.