New, Non-lethal Weapon

That "dazzles" and confuses the enemy.

The New Scientist:

The US government has unveiled a "non-lethal" laser rifle designed to dazzle enemy personnel without causing them permanent harm. But the device will require close scrutiny to ensure compliance with a United Nations protocol on blinding laser weapons.

Why does the UN ban non-lethal potentially blinding weapons? What causes more harm an M-16 that can kill and maim or PHASR laser that might only cause blindness?