In the past six weeks, Americans have witnessed two jarringly different -- but completely accurate -- views of al-Qaeda's terrorist network. One image was that of terrorist leaders being hunted down and killed by satellite-guided, pilotless aircraft. The other was of an agile foe slipping past U.S. defenses and increasingly intent on striking inside the United States. New assessments of al-Qaeda by the top U.S. counterterrorism experts offer grounds for both optimism and concern a year after President Obama took office. Officials say al-Qaeda's ability to wage mass-casualty terrorism has been undercut by relentless U.S. attacks on the network's leadership, finances and training camps. But even in its weakened state, the group has shifted tactics to focus on small-scale operations that are far harder to detect and disrupt, analysts say. The deadly November shooting rampage at Fort Hood, Tex., and the failed Christmas Day attempt to bomb an airliner -- both examples of the low-tech approach -- have raised the fear level in Washington and across the country. Some terrorism experts say the worst could be still to come as a wounded jihadist movement thrashes about in search of a victory. "The noose is tightening, and al-Qaeda's leadership is accelerating efforts that were probably in place anyway," said Andy Johnson, former staff director of the Senate intelligence committee and now national security director for the Washington think tank Third Way. In the past year, Johnson said, the "good guys have been scoring the points," killing key al-Qaeda leaders and disrupting multiple plots. But pressure on al-Qaeda in Iraq and Pakistan has forced terrorist operatives to flee to new havens, such as Yemen, and step up the search for weaknesses in Western defenses. While battered, "the enemy is unwavering and determined," he said. On target The U.S. ability to strike al-Qaeda's nerve center was on display recently with news of the apparent death of the leader of the Pakistani Taliban, a close ally to al-Qaeda in the lawless frontier along the Pakistan-Afghanistan border. Hakimullah Mehsud, who suffered severe injuries in a missile strike in mid-January, was the second leader of the group to find himself in the path of a CIA Predator aircraft in the past six months. He also was closely linked to the Dec. 30 suicide bombing that killed seven CIA officers and contractors in Afghanistan's eastern Khost province. U.S. drones have struck al-Qaeda and Taliban targets inside Pakistan 12 times this year, putting the Obama administration on a course to surpass 2009's record-setting 53 strikes, according to a tally by the Web site Long War Journal. In testimony before two congressional panels last week, top U.S. intelligence officials said the campaign has shaken al-Qaeda's core leadership, the small band of hardened terrorists led by Osama bin Laden. The attacks, combined with a successful squeeze on al-Qaeda's cash supply, have impeded the group's ability to launch ambitious, complex terrorist operations on the scale of the Sept. 11, 2001, strikes on the World Trade Center and the Pentagon, the officials said. "Intelligence confirms that they are finding it difficult to be able to engage in the planning and the command-and-control operations to put together a large attack," CIA Director Leon Panetta said Tuesday in testimony before the Senate Intelligence Committee. But intelligence officials also warned lawmakers of worrisome new evidence of al-Qaeda's ability to adapt. In an annual "threat assessment" to Congress, spy agencies described the emerging threat as more geographically dispersed and also low-tech, favoring lone operatives and conventional explosives. 'Short-term plots' Director of National Intelligence Dennis C. Blair, who presented the assessment to House and Senate panels, said the attempted bombing of Northwest Airlines Flight 253 over Detroit is emblematic of an evolving threat that relies on "small numbers of terrorists, recently recruited and trained, and short-term plots." The new tactics are less spectacular but also much harder to detect and disrupt, he said. The suspect, Umar Farouk Abdulmutallab, is a Western-educated young man who was apparently recruited because he had a U.S. visa and no record of ties to terrorist groups. Officials say that he was trained and equipped by one of al-Qaeda's rising affiliates, al-Qaeda in the Arabian Peninsula, and that he had a bomb made of a common military explosive sewn into his underwear, deliberately designed to thwart the kinds of safeguards put in place after 9/11. The foiled plot came on the heels of the Fort Hood shooting rampage. That attack, and the arrest of an Army major apparently inspired by al-Qaeda, crushed the widely held perception that Americans were immune from the kind of violent home-grown extremism seen in Muslim enclaves in Western Europe. Blair acknowledged that intelligence agencies are newly concerned that Americans may be traveling overseas for training and returning to the United States to carry out terrorist strikes. "A handful of individuals and small, discrete cells will seek to mount attacks each year, with only a small portion of that activity materializing into violence against the homeland," he said. Blair testified that he thought another attempted strike by terrorists was "certain" in the next six months. The assertion was a response to a question by the Senate intelligence panel's chairman, Dianne Feinstein (D-Calif.), about the likelihood that al-Qaeda would try to launch a major attack on Americans in the near future. But Blair also suggested that the rash of news about terrorist plots in recent weeks has created a false impression that the threat is new. "We have been warning since September 11 that . . . al-Qaeda-inspired terrorists remain committed to striking the United States," he said. "What is different is that we have names and faces to go with that warning. We are therefore seeing the reality." Terrorism experts and administration officials have described the Dec. 25 bombing attempt as a wake-up call that helped expose gaps in security that are now being addressed. But some analysts say the dramatic successes against al-Qaeda in Pakistan may have led U.S. officials to miss signs that the terrorist threat was morphing in new directions. Now the administration is scrambling to respond to both threats at once, said Bruce Hoffman, a Georgetown University terrorism expert and senior scholar at the Woodrow Wilson Center. "Until Northwest Airlines Flight 253, the prevailing assumption was that we could fight and win by drone attacks. But the threats are diverse and spreading," Hoffman said. "Both administrations -- Bush and Obama -- had a tendency to focus on one threat, one enemy, emanating from one place. The use of predators in Afghanistan and Pakistan is a very effective tactic. But it's a tactic, and it's not a substitute for a strategy." (Washington Post)