It’s not just Europe that has trouble reconciling religious commandments about proper dress and the public sector’s desire for non-sectarianism. The US and its courts and laws are dealing with the issue as well.
From The Volokh Conspiracy, we have a report on legislation moving through the state legislature in Oregon. Oregon has a law which prevents the wearing of religiously identified clothing by public school teachers. That law is in the process of being repealed:
[UPDATE: I originally erroneously reported that the Legislature had repealed the statute; it turns out that the repeal seems about to happen: Prof. Howard Friedman (Religion Clause) reports that, “According to the Oregonian, yesterday by a vote of 21–9 Oregon’s state Senate approved House Bill 3686 repealing an 87-year old ban on teachers wearing religious dress in the classroom.... The state House of Representatives has already passed the bill, but it now goes back to the House because of two changes in wording made by the Senate.”]
The statute, the former Ore. Rev. Stat. § 342.650, provided
No teacher in any public school shall wear any religious dress while engaged in the performance of duties as a teacher.
Though it facially discriminates against religious practices, it was nonetheless upheld against a Free Exercise Clause challenge, in Cooper v. Eugene School Dist. No. 4J (1986). I think it should have been struck down, and I’m glad it has been repealed. [UPDATE: Because some comments seem to miss this, I thought I’d stress it again: The law is presumptively unconstitutional because it discriminates against religious practices on the basis of their religiosity. If the law were religion-neutral, such as a uniform dress code for all teachers without regard to religion, then it would be judged under Title VII’s “reasonable accommodation” standard, which gives employers — private or governmental — considerable though not unlimited flexibility to impose such restrictions, including on religious objectors.]
The common argument in favor of such a law is that it is necessary to prevent students from assuming that the school endorses religion (which might even give rise to an Establishment Clause, under modern Establishment Clause caselaw). But the law is not necessary to prevent such perceived endorsement, and should thus fail the strict scrutiny that should be applied to deliberate discrimination against religious practice.
The law is only necessary to prevent endorsement to the extent that the wearing of religious garb by a teacher will be seen by reasonable students as an endorsement of religion by the government. But a child who is old enough to realize that, say, a nun’s habit means that she’s a Catholic — or a teacher’s turban means that he’s a Sikh — will generally be old enough to recognize that people of many different religions may work at the same institution, and that the school’s willingness to hire a Catholic or a Sikh doesn’t mean that the school endorses Catholicism or Sikhism.