The heads of the American intelligence community warned Congress on Tuesday in their annual threat assessments that an al Qaeda attack on the United States homeland is likely in 2010. This follows a series of incidents and arrests in 2009 that showed al Qaeda and its allies have change their tactics for attacking the homeland. For several years after 2002, al Qaeda seemed fixated on conducting another mass-casualty attack here even more horrifying than 9/11. Thus it planned a major attack for the fifth anniversary of 9/11 in 2006 in which up to 10 jumbo jets would be blow up simultaneously over the Atlantic en route to airports in the U.S. and Canada by suicide bombers recruited in the Pakistani Diaspora in England. The British foiled the attack at the last minute. Al Qaeda looked for unconventional weapons to use to attack like nerve agents.

Now, perhaps because of the pressure we are putting on the al Qaeda core in Pakistan, the bar has apparently been lowered. Al Qaeda’s affiliates and allies like the al Qaeda cells in Yemen have been encouraged to go for smaller, if still lethal, attacks. If they can’t score a home run, go for a bunch of singles. Exploit disaffected Americans like the Fort Hood gunner, blow up one plane on Christmas day and recruit Afghan, Pakistani and Somali Americans for simpler, less complex terrorism.

So if al Qaeda is now broadening the scope of its attacks, we must adjust to the change and broaden our counter measures. We need to aggressively disrupt and take down not just the al Qaeda core in Pakistan and Afghanistan, but step up the pressure on al Qaeda cells in Yemen, the Maghreb, Indonesia, Iraq, and on al Qaeda’s allies like Lashkar-e-Taiba and the Pakistani Taliban, who also operate in the West. This means putting more intelligence resources and diplomatic efforts into persuading all of our allies in the war with al Qaeda to preempt terror with take-downs of jihadist cells.