When the World Chess Federation designated Iran host of the 2017 Women’s World Chess Championship games, Mitra Hejazipour was thrilled. She is a women’s grandmaster. She learned chess at 6, played in her first formal championship at age 9, and, now 23, she has spent her life traveling the world for chess tournaments and returning to the Islamic Republic of Iran with shiny medals.

When she plays, she wears a hijab, and presumably, when the world’s best women gather in Tehran to play chess next year, they will, too. But the excitement of the chess championship news — widely celebrated in Iran — soon turned to protest. Calls for a boycott are growing louder, raising the possibility that the championship won’t be held in Tehran at all.

Some international players are saying they don’t want to wear head scarves, but they seem to be making this statement for Iranian women, too: Iranian women shouldn’t have to do this, so we’ll make a stink. But this kind of protest — outsiders who think they know best — is exactly the opposite of what most Iranian women want, and is at the heart of what’s worst about policing how Muslim women dress.

The controversy has largely been kicked off by the Georgian-American chess champion, Nazi Paikidze, who said she would boycott the games on grounds that female participants would need to wear the head scarf, which is mandatory for women in Iran. She started an online petition to “stop women’s oppression” and to challenge the chess federation’s decision. A former Pan American champion chimed in, along with Nigel Short, a British grandmaster, who told a British newspaper that the hijab is “a symbol of Islamic repression.” (Mr. Short, incidentally, has said in the past that men are “hard-wired” to be better at chess than women.)