Set Phasers to Blind
It's crazy that there's a Wikipedia Page entitled Protocol on Blinding Laser Weapons.
Why is it so crazy? Because most of the world believes it's better to be dead than blind.
Protecting Civilians
Okay, well, maybe it's not so crazy.
The Convention on Certain Convential Weapons concluded in 1980. Many nations came together to ban weapons like Booby-Traps and Incindiary Weapons. These weapons were found to cause too much "collateral damage". Hoory for protecting civilians!
Blind is Infinitely Better than Dead
Of course we don't want to harm innocent people, but imagine if we started replacing bullets with lasers -- to blind our enemies rather than kill them.
Blinded enemies are no longer viable opponents. Blinding weapons can remove combatants them from war without killing them.
Maiming soldiers is way better than creating orphans and widows, right?
Blind vs. …
Humans favor sight over all other senses -- seriously, a huge proportion of our brains are dedicated to visual/spatial processing.
So why would you want to purposefully destroy somebody's most precious connection to the world? Shouldn't we rather aim for the limbs?
Unfortunately, our current method is "bombard them with bombs and bullets and maybe they'll survive". We currently have no way of purposefully aiming for limbs during war. Right now, every combatant plays a game of roulette with prizes ranging from deafness to burns to limb loss to chronic respiratory illness to death. Wouldn't most soldiers rather play a game of "blind or not-blind"?
Becoming blind may reduce your quality of life, but it doesn't reduce the quantity of your life, and it doesn't result in chronic pain.
Blinding weapons aren't better because they maximize damage -- it's because they minimize randomness.
Blind is Forever
As a brief warning, conflict epidemiology is notoriously difficult. So be fairly skeptical of casualty counts.
The ICRC contends that most victims of war are not permanently injured:
Sixty percent of war casualties both survive and fully recover over time. With blinding from lasers there would be no recovery and no prosthetic device can replace sight.
The ICRC is very wrong.
In all of the US wars ever, about half all casualties were deaths (1.3M dead, 1.4M wounded). And how many of those 1.4M wounded do you really think fully recovered?
But let's pretend few survivors are permanently wounded, so that our recover:maime:kill ratio is 40:10:50.
Let me now remind you that our best attempt at being humane is "bombard them with bombs and bullets and maybe they'll survive".
Once again, non-lethal weapons that permanently injure others are terrible, terrible feats of engineering. But blinding weapons could change the recover:maime:kill ratio to something like 10:70:20. Wouldn't that be a signifcant improvement?
Jab, Jab, Hook!
The ICRC argues that blinding weapons are particularly harmful when they're used in combination with lethal weapons:
Blinding lasers would not actually save lives as they are intended to be used in addition to other weapons. They might even have the effect of increasing mortality rates as b linded opponents would not be able to defend themselves and thus be easily targeted by other weapons. As it is unlikely that an attacker would be able to assess at a distance whether an opponent has been rendered out of action by blinding, he would also use his other weapons. The result would therefore be just as many deaths and many more blind, thus increasing the suffering which results from battle.
The argument here is that blinding rays would be used as jab, to be followed up with lethal hooks.
Death is unavoidable in war, but it is in every military's best interest to create as many survivors as possible. Why? Because wounded casualties are more burdensome than dead ones.
It's also in every military's best interest to reduce the destruction of enemies' equipment and supplies. When you destroy something that can be reused, you're harming both sides of the conflict! If blinding lasers are used as an initial jab, then it incentivizes less-catastrophic secondary action.
In other words, if a significant portion of your opponents have been blinded, it opens up more options of secondary non-lethal force. And all combatants are incentivized to preserve enemies' lives, supplies, and equipment.
Conclusion
Imagine if US police officers used lasers instead of bullets -- how many deaths could be prevented? 1/3 of gunshot wounds are lethal (this is just counting the people that survive long enough to be rushed to the hospital). What if police officers were equipped with weapons less lethal than guns, but with more range than pepper-spray?
Imagine if the US used lasers rather than atomic bombs. Imagine if we blinded hundreds of thousands of Japanese civilians, rather than killing them? Wouldn't that something like that still do the trick? Of course, blinding an entire city would cause a few casualties (e.g. people driving), but once again, it's better than exposing them to radiation.
Of course, war is terrible and we should stop fighting forever.
But until we figure out how to achieve world-peace, we'll be the blind leading the blind.