Take a look around the Arab world.

In Yemen, al Qaeda in the Arabian Peninsula has increased control in such provinces as Shabwah and Abyan, as the central government in Sana faces a leadership crisis and multiple insurgencies. From this sanctuary, al Qaeda continues to plot attacks against the U.S. homeland, according to U.S. government assessments, ranging from plans for bombs hidden in cameras and printer cartridges to ones surgically implanted in humans and animals.

Across the Gulf of Aden in Somalia, militants of the al Qaeda affiliate al Shabaab bombarded the city of Baidoa in April, trying to expand their foothold in southern portions of the country. With a growing number of American citizens from cities like Minneapolis and Phoenix traveling to—and from—Somalia to fight alongside al Shabaab, there is an increasing likelihood that radicalized operatives could perpetrate an attack in the United States. A report last year by the House Committee on Homeland Security found that al Shabaab had recruited at least 40 Somali-Americans from immigrant communities in the U.S.

Another trend pointing to al Qaeda’s resurgence is the size of its global network. Since Sept. 11, 2001, it has expanded the number of affiliated groups. Along with Somalia’s al Shabaab, they now include al Qaeda in Iraq—which is increasing its foothold in Baghdad, Diyala and Saladin provinces. Also active are al Qaeda in the Arabian Peninsula and, in North Africa, al Qaeda in the Islamic Maghreb. The leaders of these affiliates have sworn bayat, or loyalty, to al Qaeda leader Ayman al-Zawahiri and provided him with funding, global influence, and a cadre of trained fighters. None of these organizations existed a decade ago.