Regarding the article "Abrams Pleads Guilty in Iran-Contra Case," Oct. 9: Granting immunity to Oliver North and John Poindexter crippled any possibility of effectively prosecuting the participants in this case. Treasonous acts have been committed by a number of people, but now it looks like the end of the whole affair, with North cleared and Elliott Abrams getting a slap on the wrist.It has been botched from the beginning, and almost smacks of a conspiracy to do just that - botch it. Wayne A. Lawson, Bellevue, Wash. Letters are welcome. Only a selection can be published, subject to condensation, and none acknowledged. Please address them to "Readers Write," One Norway St., Boston, MA 02115.