NAIROBI, Kenya — It was not a major arrest by ivory smuggling standards. A traveler bound for Amsterdam was stopped at Jomo Kenyatta International Airport here on a Saturday night last month with a little less than two pounds of ivory, in the form of five bangles, seven rings, seven pendants and two figurines.

The traveler’s identity was the surprising part: David McNevin, who served as a defense attaché at the American Embassy here. His arrest meant that a former official of a government dedicated to stopping the poaching that has threatened the very existence of Kenya’s elephants was engaged in ivory trading himself.

The timing of the arrest was particularly incongruous. On the same day, July 1, that Mr. McNevin was arraigned, President Obama was in neighboring Tanzania pledging an additional $10 million in aid to help halt wildlife trafficking and creating a presidential task force on the matter.

At an event in downtown Nairobi on Wednesday as part of a campaign called Hands Off Our Elephants, Paula Kahumbu, the executive director of the nonprofit group WildlifeDirect, said that ivory was leaving Africa at an unprecedented rate, part of a surge in poaching that could lead to the extinction of the elephant within 10 years if it is not halted. The United States is not exempt from the problem, she said.