[5][6][7][8][9] In 1950, Tempelsman created a new marketing niche by persuading the US government to stockpile African diamonds for industrial and military purposes, with him as the middleman.

His contacts eventually ranged from South African anti-apartheid politician Oliver Tambo to Zaire's kleptocratic dictator, Mobutu Sese Seko and the influential Oppenheimer diamond family.

Declassified memos and cables between former U.S. presidents and State Department officials from the 50's to the 90's have named Tempelsman with direct input in the destabilization of Congo, Sierra Leone, Angola, Zimbabwe, Namibia, Rwanda and Ghana.

[11][12][13] Tempelsman is one of fewer than 90 "sightholders" in the world, which means that 10 times a year he is permitted to buy diamonds directly from the powerful De Beers cartel in the City of London.

[2][7] In Southern Africa, Tempelsman has played a key role in negotiations between hostile governments and companies engaging in diamond exploration.

In the 1960s Tempelsman hired as his business agent the CIA station chief in Kinshasa, Larry Devlin, who helped put Mobutu in power and afterward served as his personal adviser.

[19] In addition to the DRC, Tempelsman has played a key role in the diamond industries of Angola, Botswana, Namibia, and Sierra Leone.

A director of the Academy of American Poets, Tempelsman also serves as a trustee of the New York University Institute of Fine Arts, and on Lenox Hill Hospital's advisory board.

[9] In 1980, Tempelsman bought, for $1 million, two 500 BC acroliths representing Demeter and Persephone; the pieces consisted of two marble heads, three feet, and three hands.

[3] Their daughter, Rena, is the widow of Robert Speisman, an executive vice president of Lazare Kaplan International Inc. who died on board American Airlines Flight 77, when the aircraft crashed into The Pentagon during the September 11 attacks.

[2][35] Maurice and Lilly Tempelsman were guests at the State Dinner given at Mount Vernon, Virginia in honor of the President Ayub Khan of Pakistan in 1961.