His problem is nukes can only be used as a last resort when your country already has started to fall, otherwise you will trigger your own country to fall quite soon after (retaliation strikes, sanctions, fallout, riots, etc)
So nobody will take it as a serious threat in response to anything less than a major attack on the capital or equivalent.
Hasn’t he threatened to use nukes multiple times over the war already? Ignoring the threats generally worked out.
His problem is nukes can only be used as a last resort when your country already has started to fall, otherwise you will trigger your own country to fall quite soon after (retaliation strikes, sanctions, fallout, riots, etc)
So nobody will take it as a serious threat in response to anything less than a major attack on the capital or equivalent.