“From a promontory high above the Pentagon, three arching spires reach skyward, their elongated tips pointing to the infinity of space. They appear as abstract art forms but only until their symbolism is made clear by their setting: They are the starring elements of a memorial to the United States Air Force, the only branch of the American military that has not had a prominent monument in the Washington area. More than 14 years in planning, the memorial is in the final stages of construction and will be dedicated Oct. 14.”