LONDON - Leon Panetta's final weeklong trip to the old capitals of Europe initially had the feel of a valedictory lap, one that would nurture the trans-Atlantic alliance and give him the chance to dine in the Italy of his heritage.

But by the time the defense secretary arrived in Rome on Wednesday, news had broken about the hostage-taking in Algeria as Pentagon officials, frustrated and alarmed, scrambled to get basic information out of Algiers. By Thursday, he was overseeing plans to deploy U.S. military cargo planes to ferry French troops and equipment to Mali, where the government of neighboring Algeria said France's armed intervention was the cause of the abductions.

On Friday, he trundled into a hastily scheduled meeting with British Prime Minister David Cameron at 10 Downing Street. Earlier, Panetta inserted language into a set-piece speech on the United States' relationship with Europe, telling students at King's College London that "terrorists should be on notice that they will find no sanctuary, no refuge, not in Algeria, not in North Africa, not anywhere."

But the reality is that pursuing those terrorists is now to be the job of the next defense secretary. Chuck Hagel is preparing for his Jan. 31 confirmation hearings. If Hagel, 66, is confirmed, Panetta is likely to exit in mid-February.

His aides say that after nearly a half-century in public service, Panetta, 74, is ready to retire to his walnut farm in Carmel Valley, Calif. There, he will help his wife, Sylvia, run the Panetta Institute, a public policy organization they founded that works to draw students into public service. "As I retire from my own career in public service, I recognize that there's a generational shift under way," he told the students in London. "There will probably not be another U.S. secretary of defense with direct memories of World War II."