Another thought: Lincoln,Grant and Sherman! Had they been able to have access to neutron weapons, and given what we know of their personalities, they would have used them to shorten the war.
Human psychology hasn’t changed in 150 years, and a 2nd civil war in this nation could be ended quickly with several well placed “demonstration” nukes!
The international community would not take nukes being used lightly. We still catch hell for using 2 little bombs on Japan.
/johnny