 Story highlights Peter Bergen: The announcement of links between Syrian insurgents, al Qaeda is worrying 
 
 He says it gives al Qaeda an opportunity to demonstrate that it is still relevant 
 
 The insurgent group, al-Nusra, is the most effective of the rebel groups in Syria, he says 
 
 Bergen: The Obama administration has been right to move deliberately on aid to rebels 
 
 On Tuesday, al Qaeda's affiliate in Iraq announced that it had merged with the Syrian opposition group Jabhat al-Nusra to form the "Islamic State of Iraq and the Levant." The announcement came in the form of an audio message from the leader of al Qaeda in Iraq, Sheikh Abu Bakr al-Baghdadi, that was distributed to key jihadist websites. Al-Golani's message was first reported by the SITE Intelligence Group, which monitors extremist websites. U.S. officials have long suspected that al-Nusra was really, in part, a front for Iraqi jihadists who had crossed the Syrian border to join the fight against Syrian President Bashar al-Assad. Washington has designated Jabhat al-Nusra a terrorist organization over its links with al-Qaida, and the Syrian group's now public ties with the terrorist network are unlikely to prompt a shift in international support for the broader Syrian opposition. Al-Qaida in Iraq said Tuesday that it had joined forces with Jabhat al-Nusra or the Nusra Front – the most effective force among the mosaic of rebel brigades fighting to topple President Bashar Assad in Syria's civil war. The announcement of the merger with al-Nusra provides al Qaeda's leaders, now headed by the Egyptian Dr. Ayman al-Zawahiri, the chance to prove they are still relevant. JUST WATCHED Report ties Syrian rebels to al Qaeda Replay More Videos ... MUST WATCH Report ties Syrian rebels to al Qaeda 03:22 
 
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 Sheikh al-Baghdadi, the leader of al Qaeda in Iraq, said that he had delayed the announcement of the formal merger with al-Nusra because he wanted to allow Syrians time to get to know al-Nusra on its own terms, without the inherent negative bias that would be caused by an early announcement of its ties to al Qaeda.
– The head of Jabhat al-Nusra, a jihadist group at the forefront of Syria's civil war, has pledged allegiance to al-Qaeda honcho Ayman al-Zawahiri. What that means isn't exactly crystal clear at this point. While Al-Qaeda in Iraq says the groups have merged under the snappy title of the Islamic State in Iraq and the Levant, al-Nusra chief Abu Mohammed al-Jawalani denies his group will be ordering new letterhead just yet, the BBC reports. "The banner of the Front will remain unchanged despite our pride in the banner of the State and those who carried it and sacrificed and shed their blood for it," he said in an audio message, the AP reports. Al-Nusra is among the most effective of the rebel groups fighting the Syrian government. It has committed more than 40 successful bombing attacks and has been on the frontline of clashes against Assad forces, adds the Daily Beast. The alliance is not a surprise (Obama labeled it a terrorist organization last year), but it is concerning, says CNN. Al-Nusra's success on the battlefield and reputation for distributing free bread makes it popular with everyday Syrians. With a powerful army in Syria, al-Qaeda would gain a strong strategic position in the Middle East, and a safe haven for long-term scheming.