It's a quote from someone else's essay which explains it as a situation where initial results are easy but finishing the job is hard. A strained analogy at best

It's a quote from someone else's essay which explains it as a situation where initial results are easy but finishing the job is hard. A strained analogy at best, and the essay is very verbose. "One of the key lessons of Vietnam was the danger of what's colloquially called "the Slippery Slope": that a given course of action might yield some early success, yet further investment into that action yields decreasingly commensurate results and increasibly dangerous obstacles whose only solution appears to be greater and greater commitment of resources and/or action. Some have called this "the Drug Trap", after the way pharmaceuticals (legal or illegal) can have diminished effect after prolonged use, requiring upped dosage in order to yield the same results. Others call this "the Last Mile Problem": that as one nears the end of a problem, it becomes increasingly difficult in cost terms (both monetary and abstract) to find a 100% complete solution. All are basically speaking of the same thing--the difficulty of finding an answer that allows our hero to "finish off" the problem in question, completely and satisfactorily."