LONDON — Everything started with a tweet. Mesut Özil knew the risks, in December last year, when he decided to offer a startling, public denunciation both of China’s treatment of the Uighurs, a largely Muslim minority in the region of Xinjiang, and the complicit silence of the international community.
Friends and advisers had warned Özil, the Arsenal midfielder, that there would be consequences. He would have to write off China as a market. His six million followers on Weibo, the country’s largest social network, would disappear. His fan club there — with as many as 50,000 signed-up members — would go, too.