A decade after the Sept. 11, 2001, attacks on the World Trade Center and the Pentagon, federal and state governments are spending about $75 billion a year on domestic security, setting up sophisticated radio networks, upgrading emergency medical response equipment, installing surveillance cameras and bomb-proof walls, and outfitting airport screeners to detect an ever-evolving list of mobile explosives.

But how effective has that 10-year spending spree been? …

One effect is certain: Homeland Security spending has been a primer-pump for local governments starved by the recession, and has dramatically improved emergency response networks across the country.