US and China must set rules before autonomous fighters cross paths. In December 2022, a Chinese J-11 fighter came within metres of a US RC-135 surveillance plane over the South China Sea, according to the US military, which criticised it as an unsafe manoeuvre. China, however, held the American crew responsible and claimed the RC-135 had suddenly veered towards the Chinese jet despite repeated warnings. Both sides released video footage, yet neither accepted the other’s.