Beirut, Lebanon:
Not long ago, most Americans had scarcely heard of Yemen, the arid, Texas-size country in the southern corner of the Arabian peninsula.
But on Friday, as news emerged of a plot to send explosives in courier packages from Yemen to synagogues in Chicago, the world's attention was focused once again on the threats brewing in Yemen's lawless, strife-torn hinterlands, where American citizens appear to be helping the local branch of Al-Qaida take aim at the United States.
It was the second time in less than a year: on Dec. 25, a Nigerian trained in Yemen tried to detonate a bomb on a commercial flight as it approached Detroit, and Al-Qaida took credit for the attempt. The American-born cleric Anwar al-Awlaki had been in contact with the would-be bomber, and some analysts believe the latest effort may also be linked to Mr. Awlaki, a charismatic preacher who remains in hiding in Yemen and has issued threats by Internet.
In recent months, American intelligence officials have grown increasingly concerned about Yemen, despite a renewed cooperation on counterterrorism with the Yemeni authorities in the past year. Al-Qaida's regional arm, which went quiet for several months after a series of American airstrikes in Yemen that began last December, has become more active since the spring, and has killed several dozen Yemeni soldiers and police officers.
The group has also stepped up its recruitment drive on the Internet, issuing an English-language magazine that includes articles with titles like "Make a Bomb in Your Mother's Kitchen." The most recent issue of the magazine, "Inspire," was published last month and includes an article by an American citizen named Samir Khan titled "I am Proud to be a Traitor to America." Mr. Khan, who grew up in North Carolina and New York City, is believed to have joined Al-Qaida's Yemeni branch last year.
One important reason for the rising concern about Yemen is the presence of Americans like Mr. Awlaki and Mr. Khan.
It is not clear how many Americans are working with Al-Qaida in Yemen, a group that is believed to comprise several hundred members, including some from Saudi Arabia and other Arab countries. The group is mostly based in the lawless provinces to the east of Yemen's capital, Sana, but has carried out attacks in the capital as well.
"These are people with both access to explosives and knowledge of how the United States works," said Bernard Haykel, a professor of Near Eastern studies at Princeton University who has written on Yemen. "And in Yemen, you can walk into a local branch of FedEx and mail something to the US. You can't do that in Somalia or in rural Afghanistan."
Al-Qaida's Yemen-based branch, which calls itself Al-Qaida in the Arabian Peninsula, does not consider the United States a key target, intelligence officials and analysts say. The group has tried repeatedly to strike at Saudi Arabia, and says it aims to topple the Yemeni and Saudi governments.
But attacking the United States draws broader publicity, and may be helpful with recruiting. Al-Qaida's regional arm took credit for a suicide attack on the American Embassy in Sana in September 2008 that left 16 people dead, including the six attackers. There have been other, less deadly attacks on other foreign embassies in Yemen's capital.
The United States government's relationship with Yemen has been troubled by mutual suspicion. The country has long been a haven for jihadists, who were welcomed there after returning from fighting the Soviet Union in Afghanistan in the 1980s. After the terrorist attacks of Sept. 11, 2001, the Yemeni government cracked down on many jihadists, but also maintained relationships with them, paroling some convicted terrorists and cultivating radical clerics. American officials complained; Yemeni officials defended their approach as necessary pragmatism in a country where hard-line Islamist views are common.
Last year American officials showed Yemen's longtime president, Ali Abdullah Saleh, intelligence reports indicating that Al-Qaida was singling out him and his family members, many of whom hold senior government positions. After that, Mr. Saleh redoubled his commitment to fighting Al-Qaida, and allowed the United States to launch airstrikes on Yemeni terrain.
But Al-Qaida's presence has also led the United States to vastly increase its military and economic assistance to Yemen, and many Yemeni and American analysts say they fear that Mr. Saleh has a financial interest in maintaining some level of threat in his country.
Another source of concern is the rising chaos of Yemen, which has a fast-growing, desperately poor population of 23 million and is running out of water.
The country's meager oil reserves, a key source of revenue for the government, are also running dry. The government has limited control outside of major cities, where powerful tribes hold sway and are sometimes willing to shelter Qaida members. An intermittent rebellion in Yemen's northwest has created a humanitarian crisis; in the south, a secessionist movement has fostered an increasingly lawless environment where Al-Qaida appears to be flourishing.
Although Al-Qaida has not claimed credit for the packages that were bound for Chicago, this latest episode "is a reminder that we have a serious problem brewing in Yemen, and the current counterterrorism measures have not been able to stop it," said Gregory Johnsen, an expert on Yemen at Princeton University.