NEW YORK – The nearly simultaneous attacks on the World Trade Center and Pentagon using commercial airliners point to a meticulously planned strike by attackers who likely deployed their own pilots, experts on terrorism said.

“No pilot, even with a gun to his head, is going to fly into the world towers,” said Gene Poteat, president of the Association of Former Intelligence Officers.

“They [terrorists] flew the planes themselves,” he speculated.

The means used in the attacks echo other recent terrorist incidents, but on a scale few imagined.

“It is shocking but not a surprise. The components of these things have been seen before,” said Brian Jenkins, a Santa Monica, Calif.-based security consultant to the Rand Corp., and former member of the Clinton administration’s Commission on Aviation Safety and Security.

Analysts said that while counterterrorism officials have examined the risk of attacks on strategic buildings using commandeered commercial jets, they were more fearful of the massive loss of life that could result from the use of chemical weapons.

“There’s been an increased focus on biological and chemical terrorism, in terms of mass casualties,” said Steven Emerson of the Investigative Project, a Washington, D.C.-based research group focused on international terrorism.

Tuesday’s attacks did not appear to require mastery of science.

Instead, analysts were impressed by the meticulous timing.

“I do find it amazing that it was this sophisticated and coordinated an attack,” said attorney Victoria Toensing, who started the Justice Department’s terrorism section as a deputy attorney general during the Reagan administration.

Many hijackings fail before planes ever get off the ground, and so the takeover of multiple planes demonstrates considerable planning and expertise, she said.

While operating the planes required substantial know-how, such attacks likely relied more on overall orchestration, said Tim Brown, senior analyst with Global Security.org in Washington, D.C., which researches proliferation of nuclear, biological and chemical weapons.

“This goes to prove the whole argument that you don’t need weapons of mass destruction, all you need is an airliner loaded with jet fuel,” said Brown.

“The actual skills of the individual operators isn’t particularly great, but the imagination to recognize the vulnerability and exploit it successfully in an orchestrated manner,” he added.

Jenkins and Brown said methods used in recent hijackings and terrorist attacks have led analysts to question the focus by the Pentagon and intelligence agencies on terrorists striking the United States with nuclear, chemical and biological weapons.

In terms of cost of materials, Brown surmised that the airliner attacks cost even less than last year’s bombing of the USS Cole in Yemen, which killed more than a dozen U.S. sailors and hobbled a high-tech vessel worth around $1 billion. That attack required only a few thousand dollars in chemicals and a speedboat.

The greatest asset of the attackers who orchestrated Tuesday’s strike was to remain undetected by U.S. intelligence and law enforcers.

The terrorists used the sophisticated concept of “redundancy” – incorporating several separate, coordinated attacks – that allowed the operation to continue even if one group was detected.

“Even if our intelligence people were following one of the guys around, that didn’t compromise the other cells. They were still able to operate,” Brown said. “The core competency of these people was to remain invisible to U.S. intelligence. If they can do that successfully, they can do whatever they want.”

Jenkins noted that the devastating strikes appeared to be the first major terrorist use of suicide attacks in the United States.

Analysts say suicide bombings or attacks were previously considered unlikely because any attacker who agrees to commit them needs to keep an unstinting level of blind faith while away from his home support base.

“We believed or hoped that the tactic of a suicide bombing would not be exported,” Jenkins said. “This is a new threat for us.”