SAN ANTONIO » When Kelly Air Force Base was ordered shut down in 1995, more than 17,000 jobs left town. Now the military presence is growing again. This time, though, the new force will not comprise fighters, bombers or boots on the ground. Instead, the city is hosting the fastest-growing domain of government and military spending: cyberwarfare.

The Air Force's new military command for computer-network offense and defense, activated in late summer, is expected to require 5,500 to 7,000 jobs, including Air Force personnel, Defense Department civilians and private-sector contractors.

Lackland Air Force Base here was named home for the new Air Force cyberwarfare operation after a competition that pitted San Antonio against communities with better-known bases in Colorado, Illinois, Louisiana, Nebraska and Virginia.

In fact, when the Air Force began looking for a place to base its new headquarters for computer-network warfare, officially called the 24th Air Force, San Antonio was not even on the list.

“;But we had a secret weapon - a lot of retired colonels, lieutenant colonels and majors who had shed their uniforms and now are in key positions at the Chamber of Commerce and all across the business community,”; said John B. Dickson of Denim Group, a computer software and network security firm here. “;They were able to make the business case very strongly in San Antonio's favor.”;

The Obama administration this year elevated computer-network warfare to be its high frontier of national security priorities, with far-reaching effects on military operations - and how the Pentagon does business.

San Antonio's experience in lobbying for the new headquarters proved how the traditional “;Iron Triangle”; of military contracting - the Pentagon, Congress and the military industry - is being replaced by a new silicon circle that requires harnessing the efforts of municipal governments, business leaders and universities to ride the next wave of large military contracts.

“;You have to pull together all the disparate interests in your community - academic interests, public-sector utilities, the military, other federal agencies already operating in town and the business community,”; said Matt Pirko of ManTech Security and Mission Assurance, another local computer-network firm.

Julian Castro, the mayor of San Antonio, said community leaders found it easy to sell the lobbying effort, not just in Washington but to their own citizens. San Antonio has a history of energetically supporting its military bases, he said. But even more, cyber operations are viewed as a more intellectual and clean, even “;green,”; sector of the American military than traditional combat.

Castro said the effort to sway decision-makers was built on arguments that San Antonio not only offered excellent computer security expertise and the municipal infrastructure to support it, but was also producing network warriors for the future through new programs at its high schools and local colleges.

Ravi Sandhu, executive director of the Institute for Cyber Security, at the University of Texas at San Antonio, said the recession had forced the state to cut back money for a number of academic programs, but not in computer security, and not here.

One draw for the Air Force was the institute's Center for Infrastructure Assurance and Security, which developed the “;Dark Screen”; exercise adopted by municipalities in 11 states to learn how to protect critical city infrastructure from computer-network attacks.

The center's assistant director, Dwayne Williams, said his program was being used in so many cities, including several that competed for the new Air Force command, that his organization was prohibited from assisting hometown officials in making the pitch to the Air Force because of insider knowledge on weaknesses in computer security systems of those other cities.

At Lackland Air Force Base, signs have been going up, identifying the new 24th Air Force headquarters and its subordinate units, the 688th Information Operations Wing and the 67th Network Warfare Wing. The new headquarters will command two other communications groups, based in Galveston, Texas, and Oklahoma City.

Maj. Gen. Richard E. Webber, commander of the 24th Air Force, said the choice of San Antonio was based on “;proximity to other cyberoperational missions, as well as access to communications and bandwidth capabilities, infrastructure and the local scientific and technical base.”;

It did not hurt that the National Security Agency already has significant operations in San Antonio, including a unit of its Central Security Service, whose missions include protecting government computer systems and producing foreign signals intelligence.

Within the alphabet soup of American spy agencies, the NSA takes the lead in electronic intelligence and computer-network warfare. Its director is expected to be assigned the second task of being in charge of the Pentagon's new U.S. Cybercommand, overseeing militarywide computer-network operations. The 24th Air Force will be the service's operation in support of that command's mission.