EVERY TIME YOU THINK you have the country pegged, it lets you down. Greensburg, Indiana, for instance. That is the Corn Belt town (pop 9,360) to which Robert Russell Garwood, the "last POW," returned from Vietnam thi week, among accusations and formal charges that he defected to the North Vietnamese after his capture in 1965, and that he helped imprison American soldiers. One month before his capture, Mr. Garwood wrote his uncle that he was heading home. He has made it a bit late, returning to a place that from its pictures looks like an architectural version of "American Gothic."

Going by firm, conventional prejudice, you would expect Mr. Garwood's reception in Greensburg to lie somewhere between a cold shoulder and a lynching. Instead, almost every Greensburg citizen interviewed has expressed sympathy, on the one hand, and a sense of fair play, on the other. Even the leadership of the local American Legion post, veterans all, have spoken forcefully of withholding judgment until the formal charges are proved or not. Nor do these sentiments seem to have anything to do with Greensburg's having liked Mr. Garwood so much that he could do no wrong or be forgiven anything. From all accounts Bobby Garwood was generally regarded as a misfit and a troublemaker when he enlisted in the Marines at 17.

But a great deal has changed since then-in Mr. Garwood, to be sure, and in the country as a whole, of which Greensburg may be a microcosm. Like the rest of the country, Greensburg lived painfully through what Michael Arlen called our "living-room war," seeing our strugles in Vietnam up close, in all their tragic hopelessness. Undoubtedly the Vietnam novels and movies of the past three years have reinforced and dramatized those memories. If the people of Greensburg thought they knew that war was hell before, they saw a whole new side of hell in the war so few honored or wished to speak of, in which a prisoner of war could feel more isolated from his own country than any POW in history.

Whatever Mr. Garwood did or did not do in his North Vietnamese prison is, for the moment, beside the point. The point is Greensburg, where they are showing compassion for another victim of the war.