After the Sept. 11, 2001, terrorist attacks, the United States embarked on a complex task: protecting an open society of 292 million people living in a nation with more than 200 ports of entry and 7,500 miles of borders.

And doing it in a way that does not unduly interfere with the free flow of ideas, people and commerce.

And devising terrorism prevention and response programs that not only work today but can also meet changing threats in a long-term effort.

The federal government is backing a multitude of domestic defense initiatives, many of which rely on information technology. The Homeland Security Department, created in November 2002, received $37 billion for fiscal 2003 and has a similar budget for this fiscal year.

Homeland security spending is the subject of much discussion among think tanks, industry groups, emergency responders and government officials. Whether the money spent on homeland security is sufficient, inadequate or overkill is an important question that's difficult to answer. Some homeland security initiatives have recently commenced, but others won't be fully deployed for years.

James Carafano, senior research fellow at the Heritage Foundation, likens the war on terrorism to the Cold War, in which the tools for addressing the conflict evolved over several years of trial and error. "That is the period we are in right now," he said.

The following sections assess IT-oriented homeland security efforts in six areas: entry/exit monitoring, transportation, emergency response, bioterrorism, critical infrastructure protection and business continuity. Investments in those fields are recent, and progress may be uneven at times, observers say.

Entry/exit system: High visibility, tight budget

The ability to screen people who enter the country is an important line of defense.

"The most important thing we can do in terms of homeland security is to make sure terrorists don't get into the country," said Charles Pena, director of defense policy studies at the Cato Institute. "All the hijackers on [Sept. 11, 2001,] came into the country through legal means. If you keep the bad guys out, you will have gone a long way toward protecting the homeland even if you do nothing else."