For a period of time, being al-Qaeda’s third-highest leader in the hierarchy meant a short career, as US counterterrorism efforts either captured or killed a series of them. Today, that shifts to the network’s number-two leader, Nasir al-Wuhayshi, who had been leading AQ’s efforts in Yemen as well as directing global terror operations for the whole network. The US took out Ayman al-Zawahiri’s top lieutenant with a drone strike, AQ admitted today, announcing Wuhayshi’s replacement in the same video message:

A video released by al Qaeda on Tuesday said Wuhayshi had been killed in a U.S. airstrike along with two other militants and that a successor, Qassim al Rimi, had been appointed.

In the video, fellow commander Khalid Batarfi paid tribute to the slain jihadist, saying he had “participated with the first generation in fighting America” since the 1990s. Batarfi also threatened revenge on the U.S., saying al Qaeda would “target your economy … attack your interests and destroy them.”

NBC News partner Flashpoint Intelligence confirmed the authenticity of the video from the official media arm of the terror group’s Yemen affiliate, al Qaeda in the Arabian Peninsula (AQAP).

In addition to leading AQAP — considered to be the terror organization’s most important affiliate — Wuhayshi was said to be “operations manager” of al Qaeda Central, reporting directly to Ayman al-Zawahiri. Zawahiri assumed command of the terror group after bin Laden’s 2011 death and retains leadership of al Qaeda in Pakistan, but his mobility is limited and he is unable to plan much of anything, said a U.S. counterterrorism official. On the other hand, said the official, Wuhayshi, “by virtue of where he is,” can plan external operations against the West.

This is a very big deal, CNN’s Jomana Karadsheh reports from Amman — perhaps the biggest win against AQ since the Osama bin Laden raid. Wuhayshi had been at one time the personal secretary of bin Laden, and knew all of the players in the AQ network:

The new #2 is hardly unknown to the US, which has a $5 million bounty on Rimi’s head. Until now, Rimi has played a “regional role” in AQ, but he no doubt will try to come up to speed on plots to attack the West. For now, he’ll have his hands full with the chaos in Yemen and AQ’s attempts to play it to their advantage as much as possible. At one time, NBC reminds us, Yemen had Rimi in prison, but …

Al-Rimi was one of 23 jihadis who broke out of a jail in the Yemeni capital of Sanaa in 2006 by tunneling their way towards a nearby mosque. Among the other escapees were men convicted for their role in bomb attacks on the destroyer USS Cole in 2000 and the French tanker Limburg in 2002.

His name was added to the U.S. list of “most wanted” terrorists in May 2010. …

Last year he railed against Yemen’s Houthi rebels, promising that al Qaeda would fight them to the death for control of the country, which has since descended into civil war.

So once again, it’s a significant victory for the US and a body blow to AQ, but it’s not a knockout punch. It’s still impressive, perhaps even more so after losing much of our ability to conduct intel operations in the failed state of Yemen.