Origin/meaning of (possibly) British slang ''straffer''

In the movie Merry Christmas, Mr. Lawrence (1983), when Col. Lawrence hears that Major Jack Celliers is being transferred to their POW camp, he says something like, “Jack Celliers?! Straffer Jack?!”

He later struggles in trying to explain the term *“straffer” (pronounced “STRAY-fer”, as though there were only one “f”) to one of his Japanese captors, either Sgt. Hara or Capt. Yonoi, that it means “a man’s man.” It’s then kinda passed over, and there might have been some double meanings in that interpretation based on some events in the movie.

But the GQ: Is this indeed British military (or otherwise) slang? If so, what’s the origin. From the context it doesn’t seem any connection to “strafe,” a word that often popped up in WW II movies. Or did van der Post just make it up?

*That was the way Sir Laurens van der Post spelled it in the story “Shadow of a Bar,” the basis for the movie.

This is WWI British Army slang. To “strafe” someone is to give them a hard time, or punish them (from the German ‘strafer,’ to punish). It was most likely picked up from the pre-war German press’ call “Gott strafe England,” as German popular opinion held that the perfidious British did not want Germany to “have her place in the sun,” i.e. expand her small overseas colonies into a rival Empire. (An opinion not without some justification).

It was most often used in the Great War to refer to an artillery barrage by the enemy (the “morning strafe”); or to refer to a soldier or officer who was in trouble with authority (generally the sergeant, or Commanding Officer, respectively).

Eric Partidge, in his excellent “Songs and Slang of the British Soldier, 1914-18” (3rd edition, 1931) says this:

In WW2, Colditz castle, the high-security POW camp, was a “Straflager,” a punishment camp.

I’ve never seen a reference to the word prior to WWI, though.

Another possibility is that the Major was being referred to as to have practiced strafing when flying over the enemy i.e. giving them a ‘hard time.’

strafe ( P ) Pronunciation Key (strf)
tr.v. strafed, straf·ing, strafes
To attack (ground troops, for example) with a machine gun or cannon from a low-flying aircraft.
n. An attack of machine-gun or cannon fire from a low-flying aircraft.

In the Germany army, straf battalions were penal units. I’ve no idea whether that’s a more plausible explanation than ‘strafe’, but it’s an option.