A driving issue in the 2004 presidential election, homeland security has been largely overlooked by John McCain and Barack Obama on the 2008 campaign trail.

But some experts in home land security and counter-terrorism are concerned the candidates aren't telling us nearly enough about how they will spend the nearly $40-billion homeland security budget.

While surrogates for the candidates have addressed industry conferences or think tank forums, neither campaign has made homeland security or terrorist threats much of an issue in the months leading up to the Nov. 4 election. "That's because there's not much controversy," says Brian Ruttenbur, a homeland security analyst at Morgan Keegan & Co., a Memphis, Tenn.-based securities firm.

Neither McCain nor Obama is going to cut homeland security spending, Ruttenbur predicts. "It's probably not going to grow a whole lot under either administration either." he adds.

Both campaigns have announced their commitment to protecting the nation's critical infrastructure, including water supplies, chemical plants, information technology networks and mass transit systems.

They also call for better cyber-security, border security and interoperability improvements to emergency communication systems that will allow first responders to talk with each other and federal agencies at a disaster scene. Both candidates also call for improved intelligence gathering, more cooperation -- between federal and local authorities and between the U.S. and other governments to halt the proliferation of nuclear weapons and trafficking in materials that could be turned into a weapon of mass destruction.

"John McCain's view is we need to win the war - the war by radical Islam against us," former Oklahoma Gov. Frank Keating, a McCain surrogate, told a Center for Strategic and International Studies (CSIS) forum across the street from the White House last month.

But some experts are concerned that too much emphasis is being placed on nuclear weapons of mass destruction, identified by the Bush administration as the gravest threat to the U.S., at the expense of other threats.

"For years we have called bio-weapons the poor man's nuke," says Randall Larsen, a longtime homeland security and biological warfare expert at the University of Pittsburgh's Center for Biosecurity. "I don't worry about Osama bin Laden building a nuclear weapon, but he can build a bio-weapon from scratch."

Larsen notes that a January 2005 report by the National Intelligence Council was concerned that a terrorist would obtain a biological or, "less likely," a nuclear weapon.