self-licking ice cream cone
n.— «For grateful military leaders, there was merit in reinforcement for its own sake. One senior general compared the existing force to a “self-licking ice cream cone”—so small and weak that it consumed most of its resources in the effort to supply and defend itself.» —“Deadline Squeezes Somalia Mission” by Barton Gellman San Francisco Chronicle (California) Oct. 8, 1993. (source: Double-Tongued Dictionary)