Last week, Americans commemorated the twenty-fifth anniversary of the 9/11 attacks carried out by Islamist extremists.

Afterward, our leaders rightly emphasized that America’s quarrel wasn’t with Muslims generally. And millions of peaceful, patriotic Muslims have made America their home.

But tolerance can’t require us to ignore a legitimate question about assimilation. Some beliefs found in significant parts of the Islamic world — about the treatment of women, Jews, religious minorities, or those who leave the faith — are completely at odds with American principles.

America has always welcomed immigrants of every faith. But immigration only works when newcomers are willing to embrace our fundamental values — not when they seek to remake our country according to values Americans have rejected.

Twenty-five years after 9/11, asking whether we’re doing enough to encourage assimilation isn’t bigotry. It’s common sense.