The foiled bid to blow Northwest Airlines Flight 253 from the skies above Detroit on December 25, 2009 was very nearly the second most serious incident in the United States associated with Al Qaeda since 9/11.

Though appropriately dubbed the single "biggest failure" by U.S. intelligence and homeland security officials since then, its fallout has already unquestionably begun to affect U.S. antiterrorism strategies. Indeed, it is a shift that will continue to evolve for years to come.

Obama's new strategy

Since U.S. President Barack Obama assumed office in January 2009, he has significantly altered many dimensions of his predecessor's "war on terror." From the beginning, Obama has pledged to shutter U.S. detention facilities at Guantanamo Bay, while withdrawing U.S. troops from Iraq. Instead, he has already begun shifting the focus of counterterrorism measures to Pakistan and, in particular, Afghanistan, which has witnessed a significant troop escalation.

Meanwhile, the 44th U.S. president has emphasized a comprehensive use of "soft power," including diplomacy and economic aid, along with U.S. military might--something conspicuously absent over much of the past decade. The goal is to divide and weaken Al Qaeda, its regional loyalists and emulators worldwide.

In addition, the Obama administration has also sought to improve America's overall image in the Muslim world. In particular, the White House has worked energetically to enhance relations with the nations of the Arab Street--relationships that had previously all but collapsed following the 2003 invasion of Iraq and a near-total lack of progress on the Palestinian question.

This can be seen even in the choice of language the administration uses regarding terrorism in the international arena. It abandoned, for instance, monikers such as the "war on terror," "jihadists" and "Islamic terrorism," replacing them with words with greater resonance and nuance like "emergency action overseas," "rebels" and "extremist forces."

On December 1, 2009, for instance, Obama made a pointed speech at the U.S. Military Academy at West Point, declaring a new strategy against terrorism in South Asia. He reiterated that America's antiterrorist goal is to vanquish Al Qaeda cells in Afghanistan and Pakistan, thus preventing them from establishing a beachhead with which to threaten the United States and its allies.

Obama pledged to accomplish this by sending 30,000 additional American soldiers to Afghanistan. Meanwhile, he announced a timetable during which U.S. troops would begin to withdraw from Afghanistan over the course of 18 months.

Overall, Obama's new strategy consists of three main parts: The first involves the strengthening of military strikes. The second lies in improving the Afghan economy through economic aid, and diplomatic efforts with its allies and neighboring countries. Beyond that, Obama has expressed a need to enhance the basic governance and security management abilities of the Kabul government.

The third is to push for greater antiterrorism and counterinsurgency operations in Pakistan in order to dismantle the "terrorist paradise" flourishing on the lawless border regions in northern Pakistan near the Afghan border.

This partially realized vision, however, was seriously disrupted by December's terrorist attack.

Yemen's Al Qaeda franchise

In the aftermath of the Northwest Airlines incident, the United States raised its security threat level, coupled with various other measures aimed at smashing the Al Qaeda branch in Yemen. It has since become clear that the perpetrator of the attempted attack, a 23-year-old Nigerian named Umar Farouk Abdulmutallab, had spent some time in Yemen prior to the incident.

On January 3, the United States announced the adoption of new, more stringent security checks. Under the new measures, passengers arriving from 14 countries--including Nigeria, Yemen, Pakistan and Saudi Arabia--are now subject to full-body searches at international airports. Meanwhile, the U.S. Embassy in Yemen was temporarily closed.

For some time now, Washington has supported harsh antiterrorist operations in Yemen, with the intensification of both air and land attacks on terrorist redoubts. Since the latest episode, Obama has done an about-face by declaring all-out "war" on Al Qaeda with higher profile language. This language struck many as eerily reminiscent of the seemingly long departed Bush era.

And although the Yemeni Government has launched multiple crackdowns, leaving Al Qaeda in serious disarray since 2001, things on the ground are changing yet again. Moreover, in the past two years, Al Qaeda in Yemen has expanded once more, as the country on the southern end of the Arabian Peninsula has deteriorated into lawlessness and violence.

The year 2008, for instance, saw a rash of terrorist incidents; these soared in number last year to 100 attacks--attacks that, on more than one occasion, targeted foreign tourists and embassies.

Yemen, notably, has long been regarded as the strategic haven for Al Qaeda. In addition, the rugged, mountainous land has strong ties to Osama bin Laden's family.

There can be no question that Yemen's cultural and ethnic characteristics, coupled with its geographic location, have made it a special home for Al Qaeda's global jihad movement.

One of the biggest challenges for Yemeni security officials has been a 2006 jail break by Nasir al-Wuhayshi. He, along with coconspirators, has managed to reconstitute their terrorist network, thus resurrecting Al Qaeda operations there.