Last week, Newsnight devoted a whole programme to the issue of migration in general and immigration to Britain in particular. What was most pointedly revealed was the conflict between the apparent expediency of migration (from an economist's perspective) and the social tensions created, at least initially, by an "influx" of immigrants.

Such social tensions are the inevitable product of ignorance (mostly on the part of the indigenous population) and the isolationism fostered by many of the immigrants. There is no reason why such difficulties should impede the overwhelmingly good effects of migration. Countries' borders are an artificial construct, brought about by a queer sense of tribalism. Social evolution will erode this anachronism, and politics should assist the process.

This week's Question Time also debated the issue. In accord with the tradition of this programme, idiotic points far outnumbered intelligent ones. Ken Clarke and others banded about the phrase "No right to be here...", assuming that he had the right to determine others' locations, when it is a mere historical quirk that Mr Clarke resides in this country in the first place.

Only one member of the audience spoke sense - a university lecturer - who referenced the "illiberalism" of the populist and negative attitude to immigration in Britain (and indeed most, if not all, western countries). George Bush recently succumbed to such populism by sending troops to "guard" America's border with Mexico, which stretches nearly 2000 miles.

There is no justification for isolationism; it is economically inefficient and socially perverse. The sooner words such as xenophobia, borders and nationalism are rendered obsolete, the better. With the natural force of globalisation, it is only a matter of time.