But China’s leaders are treading carefully for now…For decades Russia pumped arms to China. On average it sent $2bn-worth every year between 2001 and 2010, with a bonanza $7bn deal in 2015. Now the tables have turned. Russia has lost over 9,400 pieces of equipment, including more than 1,500 tanks, during its botched invasion of Ukraine. It is desperately short of ammunition. America says it has intelligence suggesting that China is considering whether to supply Russia with weapons. That could change the course of the war. It would also trigger a deeper crisis in China’s relationship with America and Europe.