The phrase "homeland security" was born - along with the knowledge of our vulnerability - with the Sept. 11, 2001, attacks.

Attacks on the homeland were no longer something that happened, by and large, elsewhere. And security measures - often viewed in the past as expensive, inconvenient and, even, annoying - were now a necessity.

Many of those whose job it is to think about security agree that the United States is safer than it was a decade ago. But the threat continues to evolve, they are also quick to say, and so must the safeguards against it.

They don't agree on what those defenses should be, or on the best way to use resources. But that may be a good thing: The debate keeps the topic of security at the forefront, helps prevent complacency and results in a layered response to keeping us safe.

"9/11 jolted us out of our slumber," Sen. Joe Lieberman said in a recent interview, but as time passes, the danger is that "people will start to feel the threat is gone.

"The threat will go on for a generation or more, and we have to keep our guard up."

"We were a country that pretty much dealt with dangers beyond our shores," said national security expert Stephen Flynn.

Today's reality, Flynn said, is something new. And it would be wrong, he said, to treat the terrorist threat "as something the professionals will take care of."

"At the end of the day, risk is something we're all going to have to manage together," he said.

An open port

Ten years ago the Naval Submarine Base and Electric Boat, like the rest of the country, were unprepared for a large-scale attack.

"Really, the port was open," said Navy Rear Adm. Michael E. McLaughlin, the former commander of Submarine Group Two.

"We didn't have barriers," he said. "We didn't have security patrols out there. We essentially considered ourselves as a bastion."

The submarine base had no barriers around the submarines or even a main gate that could be closed in a crisis. Electric Boat was so open that in 1982, a pacifist got close enough to a submarine to hammer its sonar equipment.

On Sept. 11, "We weren't prepared for it at the shipyard to be able to set security if the event spread," said Capt. Marc W. Denno, who was in charge of a submarine being built at EB in 2001. "We kind of were making it up as we went for the first few hours."

Sailors and guards at EB, Denno said, "didn't even have guns."

Tighter security came with a price, even beyond dollars. It would take longer to get things done, from getting trucks full of parts onto bases to sorting the mail.

"Security is expensive and 9/11 told us it's necessary," said Denno, now the commanding officer of the submarine base.

The base built gates and surrounded the subs with large black buoys, among a myriad of other protections put into place.

The Navy required that private shipyards increase their security. EB did "everything necessary to protect our environment and our people," said Michael Toner, who was president of the shipyard then.

The base joined groups created after Sept. 11 to share information to help prevent a future attack. Local fire chiefs, recognizing that the region was vulnerable, began working more closely together, said Subase Fire Chief Tom Clapsadle.

"This is not a base that is isolated from the community anymore," said Lt. Paul Tidd, the assistant security director. "We're all in the same boat."

The base has to be prepared for everything, Denno thinks, whether it's someone in a rowboat trying to damage a submarine or in a car with a bomb outside the gate. The mass shooting at Fort Hood in 2009 showed that threats can just as easily come from within, which is much more difficult to guard against.

Being ready for everything is a formidable task.

"We have a mission to complete on the waterfront, and we have a mission to protect, and we also have a mission to be fiscally responsible," Denno said.

"And every one of those is pulling on the other. What will the threat in the future be? The fiscal resources, what will they be? There's a lot of unknowns."

Ports: A priority for Coast Guard

"Our number one mission in 2000 was search and rescue," said Lt. Todd Hartfiel, commanding officer of Coast Guard Station New London. "That was what we did. That was what the Coast Guard was known for."

Today, Hartfiel said, the station spends most of its time keeping the port and nearby waters secure. The crews escort the submarines and Navy vessels. They patrol the Thames River, searching for anything suspicious on shore and making sure boaters stay clear of the base, EB and Millstone Power Station.

The Department of Homeland Security was created to lead the nationwide effort to protect the country, and the Coast Guard became the only military organization within the new department.

"We're not like Navy SEALs or undercover cops," Hartfiel said. "We want the public to see us … It's kind of like the state trooper ... You don't know when he's going to be in the ditch waiting for a speeder to come by."

When he joined the Coast Guard, Hartfiel sometimes left the keys in the boats. Who would tamper with a Coast Guard boat? Fencing and gates at the stations were more of a luxury than a necessity.

"I don't think we take it for granted - our safety - anymore," he said.

Less than five miles from the station, cadets learn how they, as officers, will defend the country's maritime borders. The challenge for the Coast Guard Academy is maintaining the tight security of a military base while making it feel like a college campus.

Cadets don't leave backpacks outside buildings anymore, and staff are quick to question anyone who looks like they don't belong, said Chief John Appicelli, the academy's police chief. The academy plans to install a key card access system for the barracks in the near future.

The academy's force is more professional than before Sept. 11, when it was harder to get funding for crisis training. The chief is confident that these steps - from vehicle searches to patrols and improved sensors - and the increased police training have made the campus a safe place.

'New battlegrounds'

Lieberman - and other members of Congress - worry that the utilities could be the next target.

The nation depends on the electric grid and financial and transportation infrastructure, "all of which are run today by the Internet and cyber space," said Lieberman, chairman of the Senate's Homeland Security and Governmental Affairs Committee.

A bill Lieberman co-authored aims to strengthen Washington's ability to protect the electric grid, energy supply lines, telecommunications, financial and transportation systems. Most of this infrastructure is privately owned; the bill proposes a public/private partnership to set national cyber security priorities.

"That's the big one I hope to get accomplished before I leave in the next year and a half in terms of homeland security," Lieberman said.

Connecticut's freshman senator, Richard Blumenthal, also thinks the terrorists could try to take down utilities and financial institutions.

"There are new frontiers, new battlegrounds, new targets," he said. "And there must be ever increasing vigilance and vigor in fighting back."

A massive cyber attack against defense contractor Lockheed Martin earlier this year showed that even defense contractors- which put more time and effort into guarding their networks- are vulnerable. These companies "got a wake-up call," Lieberman said. "The government is working with them to protect the assets they have."

Toner, the shipyard's former president and a consultant for EB's parent company, General Dynamics, said cyber security has always been a priority. Protecting data, he said, is "job one."

National resilience

Homeland security doesn't start in Washington, said Scott Bates.

Stephen Flynn, of Old Lyme, along with Stonington resident Bates, leads the Center for National Policy, a nonpartisan national security think tank in Washington. The two are calling for a "national resilience campaign."

"It starts in hometowns, with all of us being responsible for ourselves and neighbors," Bates said. "That's the original American characteristic and spirit."

They think that attacks, like natural disasters, can't always be prevented. People should be able to take care of themselves for 72 hours and help those in their neighborhoods who can't. Communities need to plan for likely risks.

Five communities nationwide - including Greenwich - have volunteered to implement some of the ideas and serve as models for other municipalities.

Blumenthal acknowledged that the federal effort has been "far from perfect," but says it is still the right away to combat the threat. A community couldn't stop an attack on the nationwide utility system, for example, he said.

"We can't wait for the attack and respond with resilience alone," he said.

Denno, the sub base commander, said what keeps him up at night is the fear that he is overlooking something.

"The potential terrorist has the advantage," he said.

"We don't get to determine the rules now. They determine the rules," Denno said.

"So what am I not thinking about, what have I not thought about, what has the rest of the organization not thought about?"

j.mcdermott@theday.com