Airport interrogations, armed air marshals and a sophisticated security net used by Israel's El Al airline would probably have foiled this week's devastating terror attacks in the United States, Israeli experts said.
Faced with El Al's stringent security procedures, experts say it is unlikely the 18-odd hijackers would have been able to board one, let alone four planes. Even if they had, an armed El Al marshal would have been on hand to disarm them, they said.
The cells of four or five attackers armed with knives could never have taken over the controls on an El Al plane as the pilots are locked in a reinforced cabin.
The U.S. attacks were so devastating because the hijackers were able to fly the planes into New York's World Trade Center on Tuesday killing thousands of people and another plane flew into the Pentagon in Washington shortly afterwards killing scores more.
Passengers travelling on Israel's national carrier El Al are required to respond to a stream of questions fired by security staff before they can board the plane. Pauses, hesitations and inconsistencies in stories are scrutinized.
"Who packed your bags? Have they been with you the entire time? Has anyone given you a gift to deliver?" are some of the queries asked of passengers before flight check-in. Security staff rummage through suitcases and hand luggage.
"This looking into the eyes of the person, you see whether he is anxious, worried, concerned or he is an innocent passenger," former Israeli intelligence chief Shlomo Gazit said.
He said the hijackers behind Tuesday's attacks would have shown signs of anxiety or stress before they boarded the plane.
"I don't believe you can send 30 fanatics to the airport and they will not show in their eyes that they have something in mind," he said.
Gazit acknowledged that it would be difficult to apply the same stringency to the huge number of internal and international flights in the United States.
Security was "far more complicated" there, he said. "You are not dealing with a limited number of flights. In the States they probably have 100,000 flights a day from dozens of international airports."
El Al fine-tuned its security procedures, which cost some $90 million a year, when Israel was faced with a hijacking campaign by the Palestine Liberation Organization and other militant groups in the late 1960s and 1970s.
El Al security agents know about every passenger on each flight even before they arrive at the check-in counters, as names are cross-referenced with lists of suspects prepared by Interpol and Israeli intelligence agencies, said Defense Ministry spokesman Shlomo Dror, a former El Al security official.
"When the passenger comes to the flight it's not the first time we know something about him," Dror said.
Dror would not reveal the profile of possible suspects used by El Al security guards, but he said security officers did not just focus on people of Arab origin.
During Dror's time with El Al security, a German man in his early 20s was caught in Zurich in 1979. He thought he was smuggling diamonds to the Jewish state on behalf of a criminal gang but the package he had been given was actually a bomb.
In 1986, a pregnant Irish woman was caught by El Al security guards in London trying to board a plane to Israel. Her Palestinian boyfriend had given her a 1.5 kilogram bomb which he had told her was a gift for his family.
"You find the people who can be the threat and when you locate this person they must go through a very thorough security check to make sure they don't have any weapons or ammunition or a bomb," Dror said.
"Security is a system that has a series of circles. If one of the circles collapses you still have other circles to stop the terrorist," said Dror.
El Al's does not comment on airline security as a matter of policy. "We do a lot of things but we don't talk about it," one official said.
The airline, which is expected to make a loss of around $160 million this year, covers about 30 percent of the security expenses. The Israeli government funds the rest.
"There is no hundred percent in security but at least you can make it very hard for the terrorists," said Dror. "In most cases they are looking for easy targets."