Ridiculous.
If you rewind back humdreds of years to the Crusaders Vs. Jihads days and told either of them the chance of survival is at WORST 95%, I can't help to think that they'd believe they're not in the right place (someone must of grabbed the wrong map).
Your Vietnam example obviously holds extremely strong, but when Vietnam was compared to COVID-19 in this thread, the typical mistake of comparing an all INCLUSIVE number (COVID-19) to an EXCLUSIVE number (US troops) was made. The all inclusive number of Vietnam was ~3.6 million as of 1997. Unlike COVID-19, every death in a war is easy to attribute.
https://en.wikipedia.org/wiki/Vietnam_War_casualties
But believe it or not, the Crusaders Vs. Jihads don't have a number due to the enormity of the unknown real number. Last I checked for all the conflicts combined, it was in the 10's of millions and the chance of survival for the unabscornd was about 8% (because they'd just wouldn't ever withdraw for anything... ever). To calculate the number you'd have to go through the list I'm posting and pick all the named wars related, but those do not include the civil wars or whatever regional wars are called over province (because a shit load used the conflict for territory alone, ideology and faith aside).
https://en.wikipedia.org/wiki/List_of_wars_by_death_toll
REALLY OFF TOPIC: If you look through that list and follow the Spanish Conquest links.... horrors upon horrors arise. The Spanish were just insane.
I'm not a history buff or anything, I just have an interest in numbers where civilization is involved.
EDIT: forgot, the reason I mentioned the Crusade wars is because those are the largest of the "siege" battles known in the "West" (the Far East has even more massive ones, but the numbers aren't as accountable... even though they're probably right).