Government counterterror experts say the threat of an attack by Al Qaeda (search) remains a significant concern, perhaps even this year, although the nation safely passed the benchmark of the Nov. 2 election.

The Homeland Security Department (search) this week lowered the terror alert for the financial sector in New York, Washington and northern New Jersey that was in place for three months. But authorities still caution the possibility of an attack is just as yond. Loy said the time period does not have a termination date.

He said a relaxed posture for financial institutions — from code orange, or heightened, to code yellow, or elevated — came because government and private-sector officials had run drills, improved security and taken other measures to "harden" the potential targets. The passing of the election, too, was on the minds of authorities.

Now, counterterrorism officials are analyzing why Al Qaeda may not have attacked and what may be ahead.

Among other efforts, experts in and out of government have been combing through two tapes released by Al Qaeda in the two weeks before the election — first by a man calling himself "Azzam the American" and another by Usama bin Laden, leader of the terrorist group.

In a recent analysis, Ben Venzke, president of the private IntelCenter (search) and a consultant to government counterterrorism agencies, said two bin Laden videos directly addressing Americans — in October of 2002 and 2003 — were followed between one and 53 days by attacks. Bin Laden's most recent message turned up Oct. 29; Venzke said he didn't know why the videos come annually in October.

None of the attacks was in the continental United States. Al Qaeda attacked a French oil tanker off the coast of Yemen and a Saudi housing complex in Riyadh after the 2002 and 2003 videos, respectively.

However, Venzke said he was particularly concerned about an attack directly against U.S. interests now because the new tapes represent "the most significant effort by Al Qaeda to address the American people in the last couple years."

For instance, Venzke noted, for the first time the initial release of a bin Laden video comes with English subtitles.

Similarly, a 75-minute video in English from "Azzam the American (search)" is also directed at Americans. It was given to a U.S. network, ABC, on Oct. 22.

If "Azzam" has been involved in Al Qaeda videos before, the shrouded speaker has not used that name. He may be a 26-year-old Californian that the FBI is urgently seeking, Adam Gadahn.

"You are talking about a group that really, really thinks about this stuff. The question is why that shift in focus," Venzke said.

Mike Scheuer, a 22-year CIA veteran and former head of the CIA's bin Laden unit, noted in a recent interview that Muslim clerics criticized bin Laden for not sufficiently warning the U.S. before the 9/11 attacks.

With these messages, "he said I am talking directly to you," said Scheuer, who resigned effective Friday to speak more freely about problems he sees with the U.S. fight against terrorism.

Scheuer said he couldn't predict if an attack would come in the window suggested by Venzke.

For bin Laden's perspective, "he has offered us chances to convert, he has warned us repeatedly, and he has acquired sufficient religious justification for attacking us," Scheuer said.

A CIA spokesman said Scheuer does not speak for the agency.

An intelligence official, speaking on the condition of anonymity, said trying to find patterns in the conduct of terrorists is difficult, and "it can be dangerous to be lulled in to a false sense of security with patterns."

Meanwhile, authorities are looking back at the threat environment over the past year and trying to find if there is an explanation for why the United States didn't experience an attack akin to the Madrid train bombings before Spanish elections, as some had feared.

The intelligence official said it may be "somewhat related" to the fact that government officials determined one of the sources of information about a pre-election threat was not credible.

Still, the official said, significant amounts of information — from other sources — have come in about a continuing desire by Al Qaeda and its affiliates to attack the United States.

Other reasons may include a disruption of Al Qaeda by U.S. law enforcement agencies, which questioned and detained hundreds during October. The Pakistani government also has rounded up lesser players in the Al Qaeda organization in the tribal areas known to harbor jihadists.

"It is all pointing in the direction of an erosion of the network they are working against," the official said.