For about a decade, Fairfax County's Economic Development Authority has employed marketing consultants to tout the county's virtues from offices overseas. This year, the authority will spend about $500,000 to fund outposts in Bangalore, India; Frankfurt, Germany; London; Seoul; and Tel Aviv.

The outposts reflect an increasingly important feature of big-county governance: a rudimentary foreign policy.

"It fits the rubric of foreign policy, because it's living proof that diversity makes us stronger," said Gerald L. Gordon, the Fairfax group's president, adding that the number of foreign firms operating in Fairfax has grown from 17 in 1979 to 332 this year.

Across the river in Prince George's County, officials are activating a foreign trade zone in Bowie that will offer tax breaks intended to allow local firms to compete with overseas companies.

"Like everybody else, we're thinking globally," said Sharon Taylor, a spokeswoman for Prince George's County Executive Jack B. Johnson (D), who visited Senegal and Gambia in March in part to promote trade.

And when Montgomery County's Douglas M. Duncan travels to El Salvador next month, he will be the first U.S. county executive to make an official visit to the Central American nation. He will meet President Elias Antonio Saca, sit down with business leaders and journey to the eastern part of the country, home to many of the Salvadorans who have moved to Montgomery.

Duncan is running an undeclared campaign for the Democratic gubernatorial nomination, so it makes political sense to visit the nation that is the homeland of the most Maryland immigrants, according to the 2000 Census.

Under Duncan's leadership, Montgomery accepts documents issued by foreign governments as proof of identity and residence, operates a welcome center for immigrants that offers English lessons and courses on citizenship and maintains an Office of Community Outreach organized according to regions of the world.

Montgomery relies mainly on a state agency for international marketing, but promoting investment will be part of Duncan's Salvadoran agenda. Rene Antonio Leon, El Salvador's ambassador in Washington, called the county "the epicenter of economic activity for Salvadorans and Hispanics in the eastern U.S." Montgomery and Prince George's counties "rank among the first in the nation in terms of the support they offer to immigrants and their support for business," he said.

Duncan isn't sure that Montgomery's programs and initiatives add up to a foreign policy. "I never really thought about it that way," he said. But he agrees that globalization and an immigrant-rich population demand a broad outlook.

"In a county like Fairfax or Montgomery, where you have such an important economic base for your region and the state, you need to look beyond your country's borders," he said. "And to provide the services that people need, you've got to look beyond them as well."

Older, established suburbs -- known in planning argot as "inner ring" or "first" suburbs -- have drawn immigrants at a faster rate in the past three decades than the cities they abut and the nation as a whole, according to Robert Puentes of the Brookings Institution. According to the 2000 Census, 45 percent of Maryland's foreign-born population resides in Montgomery.

That is one reason such suburbs are functioning more like big cities, whose mayors have long traveled overseas to market their jurisdictions and to appeal to immigrant populations back home.

Last year, D.C. Mayor Anthony A. Williams (D), for example, traveled to China, France, Italy and Spain. Duncan, over more than a decade as county executive, has visited Canada and Scotland once each and Israel three times.

Many inner-ring suburbs are "cities in content, they're cities in function, but they're not traditional cities in look," said Robert E. Lang, director of the Metropolitan Institute at Virginia Tech. To promote growth, he said, such jurisdictions must draw single people, childless couples and immigrants. For the governments of inner-ring suburbs, he added, "their stake is in being cosmopolitan -- their pride and identity is in that."

At a time of debate over illegal immigration, Duncan justifies Montgomery's policies by proclaiming that one source of the county's strength is its diversity. He defends his decision to recognize identity cards issued by the Mexican and Guatemalan governments and to encourage banks to do so as a way to help immigrants use legal banking services rather than rely on illegal or risky alternatives.

"Everything we are doing is to help people who are here work their way toward citizenship," Duncan said, adding that the "vast majority of immigrants here are here legally." Montgomery's immigrant and minority communities make up about 40 percent of the county's 930,000 residents.

When the card policy was announced in May 2003, Rep. Tom Tancredo (R-Colo.) said the cards "have nothing to do with immigrants, only with illegal immigrants. . . . They are anything but valid forms of identification. They cannot be relied upon."

Duncan said he was satisfied with the governments' procedures in producing the cards, which show local addresses, allowing Montgomery to accept a foreign government's word that someone resides in the county. Mexico's consul general in Washington, Enrique Escorza, said they are accepted by 153 counties and 32 states.

In 2001, Montgomery opened the Gilchrist Center for Cultural Diversity in Wheaton, a referral and activities center for new immigrants and others that costs the county about $300,000 a year. At the center, residents can study English, obtain legal advice and learn how to use computers.

Duncan said such programs have more to do with domestic policy than foreign policy, because they serve people already in the United States. But communities that welcome immigrants, he added, are more attractive to foreign companies than those that do not.

Montgomery's Office of Community Outreach reflects Duncan's we-are-the-world approach. One official handles African American and African immigrants; a second is the Asian Pacific American liaison; a third works with Latinos.

Duncan said he has resisted suggestions to move the office from the second floor of the Executive Office Building in Rockville, an inner sanctum where he and about a dozen county leaders work.

"Those communities need to know they've got a direct connection to the county executive if an issue arises," he said.

Staff writer Ovetta Wiggins contributed to this report.

Gerald L. Gordon leads Fairfax's international marketing effort.Montgomery leader Douglas M. Duncan will travel to El Salvador. Jack B. Johnson has promoted Prince George's trade overseas.