"They cannot have an operation fail," said Baer, "and I don't think they will. They're the A-team of terrorism."
Alarms were first raised in Canada, where as many as 20 suspected Hezbollah members have been under surveillance after as many as four suspected "sleeper cells" were activated, including one known as "Rashedan," intelligence officials tell ABC News. The members also received instruction to send their family members home to Lebanon, according to officials.
Officials have also reported that a known Hezbollah weapons expert was followed to Canada, where he was seen at a firing range south of Toronto, near the US border.
Intelligence officials said the recent Hezbollah activities were being coordinated with the help of Iran's elite Revolutionary Guards.
"Hezbollah would not carry out an attack in the west, or wherever this attack is going to occur, without approval from Tehran," said Baer, the former CIA intelligence officer.
Baer says his Hezbollah contacts told him an attack against the US was unlikely because Iran and Hezbollah did not want to give the Bush administration an excuse to attack.
While US officials say there is no credible information of a Hezbollah attack on American soil, the Homeland Security Secretary, Michael Chertoff, told Fox News two weeks ago, that "they make al Qaeda look like a minor league team."
"Hezbollah remains a threat to security in different parts of the world," said FBI Special Agent Richard Kolko, section chief for the national Press Office.
"The FBI Joint Terrorism Task Forces conduct investigations into different groups that potentially pose a threat to the US or our interests overseas; however, the FBI and DHS have no specific intelligence about any group or so called sleeper cells planning an attack. Our job is to gather intelligence, work with our domestic and international partners to identify and disrupt any terrorism event," said Kolko.
Toronto has long been considered an important city for Hezbollah fund-raising and organizing, according to officials.
Pro-Hezbollah rallies and billboards depicting Hezbollah's leader, Hassan Nasrallah, have outraged Jewish groups.
"Because of lax immigration policies, it became a center for Hezbollah operations outside the Middle East," said Malcolm Hoenlein, of the Conference of Presidents of Major Jewish Organizations.
Hezbollah was declared a terror group by the government of Canada in December, 2002, leading to an increased surveillance of suspected members.
The last major attack by the terror group outside of the Middle East occurred in Buenos Aires, Argentina in 1994.