The campaign, devised by the advertising agency Grey, features a video called “Language Matters.” It shows people painting over signs in Bengali and replacing them with Arabic. Almost no one knows what the words mean because few Bangladeshis understand Arabic. A patronizing voice-over explains, “Arabic is the sacred language of the people.”

The video shows men approaching the freshly painted walls, noticing the Arabic signage and slipping away guiltily. The men are shamed into feeling that if they were to urinate there, they would be committing an unholy act. The minister for Religious Affairs has urged men to use public toilets in the nearest mosque. I suppose he thinks he’s doing society two favors: getting men to stop urinating on the streets and getting more of them to go to mosques.

This may seem a reasonable form of behavior modification, a classic “nudge.” But the approach is deeply insensitive, because in Bangladesh, language has long been a matter of national identity.

The very seeds of our independence movement were sown when, in 1948, the government of Pakistan declared Urdu, not Bengali, the official language of East Pakistan, as Bangladesh was then known. And during the 1971 war of independence, faith and language were pitted against each other in the struggle over nationhood: The Pakistani Army would randomly stop people and ask whether they were Muslim or Bengali — as though to speak Bengali precluded being a true believer.

So the writing on the wall today contains an echo of that old conflict. It tells Bangladeshi citizens that it is acceptable to urinate on their own language, but not on Arabic. At a moment when the shadow of Islamic fundamentalism looms large, the subtext of the signage is to declare the conservative religious forces triumphant in this symbolic struggle over language.

Predictably, the ministry has been heavily censured. Critics argue that the government should spend its money on building toilets, not painting signs. And people comment sardonically that the walls of Dhaka may be covered in Arabic, but we still have nowhere to pee.

It is estimated that by 2025, Dhaka will be home to 20 million people. The government has a duty to ensure that these urban citizens — garment factory workers, rickshaw drivers, shopkeepers, truckers; in short, the people who make our city work — have access to the basic facilities they need to lead a dignified life. Researchers estimate that up to 5.5 million urban poor workers are outdoors in the city for between five and eight hours a day.