Q.It is not appropriate for schools/public agencies (army) to insist on common uniform banning religious symbols like the turban.

The modern idea of the nation-state claims that a country's borders define not just a territory, but also a shared culture and history — expressed through symbols like a flag, an anthem, a national language, or ceremonies. One of the earliest assertions of a nation's sovereignty resting with its citizens, along with their democratic rights, came from the revolutionaries in France in 1789.

Most modern states, though, are internally diverse — many religions, languages, and cultural traditions exist within the same country. A genuinely democratic state tries to define its national identity as inclusively as possible, so that every citizen can identify with it as part of the nation. In practice, however, most countries define their identity in ways that make it easier for some citizens than others to feel part of the nation — which can also make it easier for the state to extend citizenship more readily to some people than to others. This is true even of countries, like the United States, that pride themselves on welcoming immigrants.

France shows how tricky this can get. It presents itself as secular and inclusive, taking in citizens of European origin as well as citizens who originally came from places like North Africa — but it also expects citizens to assimilate into French language and culture in their public lives, while keeping personal beliefs private. The line between 'public' and 'private' is not always simple to draw, though: French schools have controversially disallowed Sikh students from wearing the turban and Muslim girls from wearing the headscarf, on the ground that these bring religious symbols into public education — while citizens whose religion makes no equivalent visible demand never run into this problem at all, showing that assimilating into a shared national identity is genuinely easier for some groups than for others.

Countries also set different criteria for granting citizenship to new applicants. Israel and Germany, for example, have historically given weight to religion or ethnic origin; Germany has a long-running, still-unresolved debate over whether the children of Turkish 'guest workers' — born and raised in Germany — should automatically receive German citizenship. …