Though al Qaeda has primarily focused on large-scale coordinated attacks since the tragic events of Sept. 11, including the attempted downing of several commercial airliners, the terrorist organization and its allies are increasingly likely to attempt small-scale attacks in the U.S., senior Obama administration officials said Wednesday. These less intricate attacks—like the plot against New York’s subway system and the failed car bombing in Times Square—are harder to detect. The threat has increased with the rise of al Qaeda-affiliated groups in Pakistan, Yemen, and Somalia, and with the higher number of American terrorists inspired by terrorist ideology. “The spike in homegrown violent extremist activity during the past year is indicative of a common cause that rallies independent extremists to want to attack the homeland,” said Michael Leiter, director of the National Counterterrorism Center. The anti-U.S. narrative has become more accessible in recent years, primarily through the Internet, and these “homegrown extremists are increasingly more savvy, harder to detect and able to connect with other extremists overseas,” according to FBI Director Robert S. Mueller III.