Qaeda Leader’s Edict to Yemen Affiliate Is Said to Prompt Alert

The intercepted conversations last week between Ayman al-Zawahri, who succeeded Osama bin Laden as the head of the global terrorist group, and Nasser al-Wuhayshi, the head of the Yemen-based Al Qaeda in the Arabian Peninsula, revealed what American intelligence officials and lawmakers have described as one of the most serious plots against American and Western interests since the attacks on Sept. 11, 2001, The New York Times reported.

American officials said that it was highly unusual for senior Qaeda leaders in Pakistan to discuss operational matters with the group’s affiliates.

The communication between the two men seems to indicate that Mr. Zawahri — whom administration officials have portrayed as greatly diminished and hindered in running a global terror network while deep in hiding — still has a strong influence over a group in Yemen that has become Al Qaeda’s most powerful offshoot.

In recent weeks, counterterrorism officials said, Mr. Zawahri has elevated Mr. Wuhayshi to what one official described as the new “general manager” of the global terror network, making him the second most important man in the organization.

The identities of the two Qaeda leaders whose discussions were monitored and the imminent nature of the suspected plot — in the intercepts, the terrorists mentioned Sunday as the day that the attacks were to take place — help explain why the United States, as well as other Western governments, took such extraordinary steps in the past few days to close embassies and consulates in the Middle East and North Africa.