For a US President who insisted on being sworn in as Barack Hussein Obama and extended an olive branch to the Islamic world in one of his first foreign policy initiatives, it is all of a piece that he should support the building of a mosque in the vicinity of Ground Zero and use an address to American Muslims at the start of Ramadan to preach a sermon in favour of religious tolerance. "Our commitment to religious freedom must be unshakeable," he said; Muslims had the same right to practise their religion as anyone else.

However instinctive such sentiments might be for Mr Obama, it still takes guts to be as forthright on this subject as he was at a time when his standing in the polls has been taking a battering and mid-term Congressional elections are just around the corner. Muslims are not, as yet, such a large or influential minority in the United States as to be a key electoral constituency for the major parties. The events of 11 September 2001, in contrast, mark a defining moment in recent US history and the memory is seared into the whole country's psyche.

The very idea of building a mosque in lower Manhattan was bound to be divisive, and it has indeed been fiercely opposed. After a long planning battle, permission was finally granted only at the beginning of this month. Yet Mr Obama, with or without his uncommon family background, is right to have said what he said, and to have said it as forcefully as he did.

Religious freedom is one of the great strengths of the United States, and one that has facilitated its successful integration of many waves of immigrants. Nor, although it requires particular generosity of spirit after 9/11, is Islam the only religion that represents a challenge to the status quo in America, now and in the decades to come. The rapid increase in the Hispanic population, which is predominantly Roman Catholic, is also bringing change to many parts of the United States, even as the traditional White Anglo-Saxon Protestant establishment is in numerical decline.

Mr Obama's election as the country's first non-white President was an extremely positive sign of US voters' openness to cultural change. But there are still those who harbour suspicion and even hatred of the diversity that he represents. It is regrettable that Mr Obama felt he had to underline the need for religious tolerance as he did, but admirable that – despite the sensitivity of the mosque's location – he nonetheless went ahead and gave it the seal of presidential approval.