i can't stop chewing on the MASH time loop situation. my star trek brain will not turn off. there is definitely some kind of temporal anomaly at play, but it's not really a time loop in the traditional sense.
effects carry over from loop to loop. they appear to age. the same wounded soldiers appear on the table three times, but the scars of past surgeries are still there. a character leaves or dies and is gone from the mash forever; their replacement arrives near the end of the war and is still there at the beginning. the dates overlap, yet their presence is sequential. the other characters remember all of them.
how far does this effect extend? if it's summer again at mash, is it summer in tokyo? is it summer in maine? if BJ is in korea two years before he arrived, who's in residency in california, marrying his wife, conceiving his child?
their family trees at home deform—different wives, different children, loved ones alternately dead and alive and never born. those inside are oblivious to what they've lost. hawkeye remembers trapper, but not his sister. what happens in korea persists; the world outside is a fragile suggestion. he tells a soldier that men at the front can't see the whole war, only the other guys dug in with them on their one little hill.
for a deep space nine fan this is irresistible. hawkeye says, wars end, but war is forever. kira asks, if the past has changed, why do i still remember it? sisko never left that ship. time itself is warped by trauma. it is not linear. you exist here. you choose to exist here.