China has yet to give any details of the corruption charges against Meng Hongwei, the president of Interpol, who disappeared on a visit home and was later said to have been arrested. Whatever the charges are, they are almost certainly not the real reason for his fate. In China, the law is what the Communist Party says it is — more precisely, what President Xi Jinping says it is. And when an official of Mr. Meng’s global stature is nabbed, it’s a political decision — even if, coincidentally, he was corrupt, as is often the case in China.

Mr. Meng understood the rules of that game. He had been a vice minister of public security in a police state and had played a role in many operations, including Operation Fox Hunt, which tried to bring Chinese officials and businesspeople suspected of corruption back from abroad. His former boss, Zhou Yongkang, was imprisoned for life on corruption charges in 2015. Mr. Meng’s last WhatsApp message to his wife was an emoji of a knife, which she understood to mean he was in danger.

Interpol has asked Beijing for an explanation for Mr. Meng’s detention but has taken no further action. The agency issued a statement on Sunday that it had accepted his resignation as president “with immediate effect” and named a replacement.