How do Nukes actually work, as far as getting the enemy to surrender?

[jurrz12]

So playing as the USA, I managed to completely salvage the war after the other Allies blew it (and I mean blew it- Egypt, Australia, China, and India had all been lost to the Axis by the time I entered the war) and by summer 1945 all of the Axis powers in Europe have capitulated.

Not wanting to deal with moving over several dozen divisions to defeat Japan conventionally, I took the historical option and dropped a bomb on Hiroshima. With no effect, I nuked two other cities. Still nothing.

Looking it up on the Internet, it seemed that nukes lower enemy National Unity, but loading up the game before+after the bombings of Japan showed NO change. It went from 90% to 90%.

Now I'm kind of baffled as to how the nukes actually work. Can someone help me?

 

[Tarnoyan Warrior]

They should lower NU to at maximum 10%(or 20 percent) could be a bug

 

[Gort11]

Japan has a bunch of national unity raising focuses which mean you usually cannot get their unity below something like 45%, which in turn means you cannot make them surrender without a ground invasion of the home islands.

I think the amount of unity a nuclear strike loses a country is somewhat random though, I think there are events that occur post-strike that either lower unity, keep it the same or even raise it. In general though, unity usually goes down. You could just have gotten unlucky three times though.

 

[elektrizikekswerk]

Nuke efficiency is tied to victory points and infractructure. So for being efficient you have to nuke a (ideally) 10/10 infra province with as many VP as possible. NU is afaik reduced by VP * infra level (or something along that line). I am fairly sure that this information is in some tooltip, but unfortunately I have no savegame with being at war and able to drop a nuke... Iirc this information is hidden in the tooltip of the drop nuke button if you have met the conditions for clicking it. But I might be wrong and it's hidden somewhere else. The nuke UI is really a mess...

Minimum NU is 10 no matter what. I don't know if Japan's NU has another limit, but I really doubt it.

 

[IrationalFear]

Looking it up on the Internet, it seemed that nukes lower enemy National Unity, but loading up the game before+after the bombings of Japan showed NO change. It went from 90% to 90%.

The base game has a cap of 90% national unity, with any sources pushing beyond 90% being kept in reserve in case something lowers it. Japan has several NU boosts in their national focus tree, which could be the problem.
Although nuke mechanics can be finicky, I would suggest trying one more nuke on them; and this time, go for their capital.