Over the years, there has been plenty of handwringing over the issue of whether al Shabaab, the Islamist terror group in Somalia, is allied with al Qaeda. Despite the fact that al Shabaab announced its intent to merge with al Qaeda in September 2008,  and al Qaeda's second in command, Ayman al Zawahiri, granted the request in Novemebr 2008, some Somalia watchers refused to acknowledge the two groups were linked. Many, also, refused to ignore al Shabaab's use of suicide attacks, its calls for international jihad, or the steady stream of foreign fighters - Arabs, Pakistanis, Americans, Brits, Swedes, etc. - entering the country.

Some al Shabaab skeptics, such as Danger Room's David Axe, changed their mind about the threat of al Shabaab after the July 11 suicide attacks in Kampala, Uganda. Al Shabaab took credit for the attacks, which killed 74 civilians at a restaurant and a rugby club as folks watched the World Cup final match.

Today, Sheikh Muktar Abdelrahman Abu Zubeyr, al Shabaab's spiritual leader, announced that further attacks in East Africa would take place. And to top it off, he announced that the unit that carried out the Kampala attacks is called the Saleh Ali Nabhan Brigade. And here is what you need to know about Nabhan:

Saleh Ali Saleh Nabhan was a senior al Qaeda leader who also held a top position in Shabaab. In the summer of 2008, Nabhan was instrumental in reaching out to al Qaeda's top leadership to broker a merger between Shabaab and the global terror group. He was killed in a US special operations raid in Somalia on Sept. 14, 2009. Nabhan was one of the most sought out al Qaeda operatives in Africa. He was wanted for involvement in the 1998 suicide attacks against US embassies in Kenya and Tanzania. The attack in Nairobi, Kenya resulted in 212 killed and more than 4,000 wounded. The attack in Dar es Salaam, Tanzania resulted in 11 killed and 85 wounded. Osama bin Laden, Ayman al Zawahiri, Fazul Abdullah Mohammed, al Qaeda's operations chief in East Africa, and Abu Taha al Sudani, the leader of al Qaeda's network in East Africa, were also involved the attacks. Sudani was killed during the fighting to oust the Islamic Courts in early 2007. Nabhan was also wanted by the FBI for questioning in connection with the 2002 attacks in Mombasa, Kenya against a hotel and an airliner. In near-simultaneous attacks, Nabhan targeted a hotel frequented by Israelis and an Israeli-chartered airplane. Suicide bombers rammed a truck into the lobby of hotel visited by Israelis; 13 were killed and 80 wounded. At the same time as the hotel attack, al Qaeda launched two Strela surface-to-air missiles at an Arkia Airlines jet. The missiles missed their targets.