'Armed with US passport'
"The president's national security strategy explicitly recognises the threat to the United States posed by individuals radicalised here at home.
"We've seen individuals, including US citizens, armed with their US passport, travel easily to terrorist safe havens and return to America, their deadly plans disrupted by coordinated intelligence and law enforcement."
Faisal Shahzad, the leading suspect in the failed car bombing in Times Square on May 1, is a naturalised US citizen, who allegedly became radicalised after years in the US and received training by Pakistani extremists.
Major Nidal Hasan, an American-born army psychiatrist who is the only suspect in the killing of 13 people at Fort Hood last year, was allegedly drawn to radical thought while serving in the armed forces.
Brennan said that "unprecedented" pressure ratcheted on al-Qaeda since Obama took office had severely limited the group's ability to move, raise funds, recruit and carry out attacks.
The network, he said, was now relying on poorly trained "foot soldiers" who might be able to slip past US defences because they do not fit the conventional profile of a "terrorist".
"This is the new phase of the terrorist threat, no longer limited to co-ordinated, sophisticated, 9/11 style attacks," Brennan said.
"As our enemy adapts and evolves their tactics, so must we constantly adapt and evolve ours, not in a rush driven by fear, but in a thoughtful and reasoned way that enhances our security and further delegitimizes the actions of our enemy."
Brennan also appeared to deliver the White House's most explicit rejection yet of "war on terror" terminology in defining its thinking about the problem.
|US citizen Faisal Shahzad is the leading suspect in the failed Times Square bombing [Reuters]
"The president's strategy is absolutely clear about the threat we face. Our enemy is not terrorism because terrorism is but a tactic.
"Our enemy is not terror because terror is a state of mind and, as Americans, we refuse to live in fear.
"Nor do we describe our enemy as jihadists or Islamists because jihad is holy struggle, a legitimate tenet of Islam meaning to purify oneself or one's community."
"We have never been and will never be at war with Islam," Brennan added.
Obama's revised approach is expected to implicitly repudiate the 2002 "Bush Doctrine" asserting the right to wage pre-emptive war against countries and groups deemed a threat to the US – part of a policy Bush called a "distinctly American internationalism" established after the September 11, 2001 aircraft attacks against the US.
On Saturday, Obama laid out the broad principles of the strategy - a document required by law of every administration – stressing international engagement over "cowboy diplomacy".
But Brennan made clear there would be no let-up in the counter terrorism fight, saying the US would need a broad campaign that "harnesses every tool of American power, military and civilian, kinetic and diplomatic".
"We will take the fight to al-Qaeda and its extremist affiliates wherever they plot and train - in Afghanistan, Pakistan, Yemen, Somalia and beyond," he said.
"We will not simply degrade al Qaeda's capabilities or simply prevent terrorist attacks against our country or citizens, we will not merely respond after the fact, after an attack that has been attempted," Brennan said.
"Instead the United States will disrupt, dismantle and ensure a lasting defeat of al-Qaeda and violent extremist affiliates," he said.
Local and foreign threats
Brennan's previewing of the Obama administration's security strategy came on the same day that a Jordanian man pleaded guilty to attempting to detonate what he thought was a bomb under a skyscraper in the US city of Dallas.
Hosam Smadi, 19, pleaded guilty in federal court in Dallas to attempted use of a weapon of mass destruction in a plea deal that could see him jailed for 30 years.
According to court papers, Smadi acknowledged leaving what he thought was a truck bomb - a decoy provided by FBI agents posing as al-Qaeda operatives - in a garage beneath the 60-storey Fountain Place building in September.
Immigration and Customs Enforcement officials said Smadi visited the US on a tourist visa in 2007, but stayed beyond the visa's validity.
Separately, a New York man accused of pledging allegiance to al Qaeda in Yemen and buying digital watches prosecutors said could be used as explosives timers, was denied bail on Wednesday in a Manhattan federal court.
New York-born Wesam El-Hanafi, 35, pleaded not guilty to conspiracy to provide material support to al-Qaeda.
He was arrested on April 30 in Dubai, where he had been working for the past four years, his lawyer, JaneAnne Murray, said.
Another New York man arrested as part of the investigation probe, Sabirhan Hasanoff, 34, a dual US and Australian citizen, was also denied bail at a hearing last week.