Most weapons of war are selective. A rifle is generally aimed at an enemy soldier, a tank will attack an enemy tank or other vehicle. Even a bomb is supposed to be dropped on a military target. But the element of choice on the part of the person in command or actually using the weapon is always there.
Nuclear weapons are different.
They cannot be used selectively. Because of the sheer scale of the destruction caused by even the smallest nuclear weapon, and because of the radioactive fallout that follows, they will always kill and injure civilians. They also affect later generations. Pregnant women who are exposed to radiation will probably either miscarry or give birth to handicapped babies. Radioactive contamination of soil, water and vegetation lasts many years.