Nukes

[Semaj]

Is it possible to get someone to capitulate with them?

[Ville Valste]

If you want to do it with nukes only, the planet will crack before the civ does, but if you want to supplement the war weariness of already long war, I guess it works.

[ghpstage]

Provided you meet the requirements you can.

The first of the major two being that you need to have a net war success of at least 40, this is very easy with nukes as each gives a flat +10.

Second is that your enemy needs to have a power rating below the world's average. This is the one that takes more effort to clear, and the one that causes questions to be asked as it means that the one city civ you may have capitulated previously can effectively block future capitulations.

[red255]

Capitulation is a function of territory, population and military power.

so if you already have the territory and population destroying his military with nukes can enable capitulation.

generally though I just do a naval assault, razing 4 coastal cities with a conventional army reduces his territory and population and causes rapid capitulation. you could I suppose soften the targets with nukes but its overkill.

[Babarigo]

IIRC I managed to do so buy launching 2 ICBM on 6 out 14 cities which made a total of 12 ICBM but honestly it's easier with a naval assault combining warships, carriers with jet fighters, modern armors and if you want paratroopers to be able to capture inland cities more rapidly and you'll achieve a capitulation in 2 turns.

[Semaj]

I have 18 ICBM’s and launched them on all of his cities multiple times, nothing, however he has one vassal on the same continent that I haven’t touched. I have a giant fleet/doomstack going around with 20 transports predominantly modern armour. In like 100 turns I’ve capitulated 7 civs, could that be why?

[ghpstage]

If you hover over the redded out capitulation option it will give you an excuse in a tooltip.

It seems most likely that their power is well above the world average threshold (not sure if its world average itself or 2/3rds of it). If this is the case the excuse given will be "We're doing fine on our own".
The battered rumps of capitulated civs or the unusual small colony are notorious for dragging world power down so much that you can practically need to annihilate civs to force capitulations later. Them having a vassal themselves will inflate their perceived power making it worse. Sounds like your best bet is to invade.

[red255]

Originally posted by Semaj:

I have 18 ICBM’s and launched them on all of his cities multiple times, nothing, however he has one vassal on the same continent that I haven’t touched. I have a giant fleet/doomstack going around with 20 transports predominantly modern armour. In like 100 turns I’ve capitulated 7 civs, could that be why?

a Vassal adds to the master's power and territory. to break a vassal from its master you need to either kill the vassal's territory to 50% of what it was at the time of vassaling, or make it larger than the master by a substantial amount.

it wonks the numbers. I've definately capitulated a master, and then the vassal leaves, and then I capitulate the vassal if I've engaged its army. on the same turn.

its just more messy.