CAIRO, Egypt - American diplomats believe Egyptian President Hosni Mubarak would have a tough time persuading power brokers in the military to accept his son as his successor, according to leaked U.S. Embassy memos.

The documents, released by the WikiLeaks website Tuesday, conclude that Mubarak might be able to install his son if he does so before his death and steps aside. If the elder Mubarak dies in office, however, the succession scenario becomes "messier," with no guarantee of military support for his son but also few other clear alternatives, the memos say.

It is Egypt's most intriguing question: Who will succeed the 82-year-old Mubarak? He is widely believed to be grooming his son Gamal for the role. A presidential election will be held next year, and it is still not certain if the elder Mubarak will run again.

One of the internal diplomatic messages described the military as the "key stumbling block" for a Gamal candidacy.

"Gamal didn't serve as a military officer and we believe he didn't complete his compulsory service," said the memo, written by former U.S. Ambassador Francis J. Ricciardone and dated May 14, 2007.

"His power base is his father, and so while he could conceivably be installed prior to Mubarak's death, the task would become far more difficult . . . once the pharaoh has departed the scene," he added, relying on the opinions of observers who were not identified.

Gamal, at 46 the younger of the president's two sons, is a Western-trained banker-turned-politician who has risen up in the ranks of the ruling party since 2002. He heads the party's powerful policy committee and was appointed its assistant chairman in 2006.

Mubarak never appointed a vice president, further complicating the question of who will succeed him. He was vice president when Muslim extremists gunned down President Anwar el-Sadat during a military parade in Cairo in 1981. Mubarak then became president and has held the office ever since.