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It seems a sword could be useful for guarding a ship or submarine against internal threats due to the reduced risk of damaging vital equipment or the hull. Swords could also be useful for defending against people armed with knives and other melee weapons, both as a tool of intimidation and as a way to help the user maintain their distance. Within a certain distance it is quite possible for someone with a firearm to be physically attacked before being able to bring a firearm to bear, but that wouldn't be an issue with a sword. Swords are also less likely to injure bystanders by their very nature.

For police use there would be the issue of issuing a lethal weapon in a role similar to the non-lethal truncheon, but it still seems like there could be a naval use? Is there a big enough niche for swords to see issue as a modern military and/or police weapon?
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