Joel Kotkin's warning of the threats to the "modern metropolis" in the face of national security concerns ["City of the Future," Outlook, July 24] inaccurately represented population trends in older American cities.

Mr. Kotkin said, "Most older American cities have lost more people than they have gained since 2000." He cited population losses in "perennial losers" such as Detroit as well as "places that enjoyed a brief resurgence" in the 1990s, such as Chicago.

His selective list omitted examples of net population growth since 2000 in older, formerly declining cities such as Hartford, Conn., and Newark as well as the nation's biggest "older" city, New York City. The Big Apple gained almost 100,000 residents from 2000 to 2004 despite the devastating Sept. 11, 2001, attacks.

Mr. Kotkin also cited the net population losses of some cities as a broad indicator of decline in all. While many older cities continued to lose small amounts of population in lower-income neighborhoods after 2000, many of the wealthier neighborhoods in these cities simultaneously gained almost precisely the same number of residents -- the very "families, retirees and immigrants" who Mr. Kotkin said are "largely deserting the urban core." Detroit added hundreds of housing units downtown after 2000. And older cities such as Chicago, Minneapolis, Detroit and Philadelphia have even more housing developments planned that will add thousands of residents to their downtowns during the next few years.

Thousands of Americans, many of them with high incomes and a high degree of residential location choice, are moving into precisely those areas of cities -- high-density, transit-dependent and mixed-use -- that terrorists recently have targeted in Western Europe. It would seem that the potential threat of urban terrorism, frightening as it may be to Mr. Kotkin, is not dissuading them from choosing older cities as places to live, work and enjoy themselves.