No nuclear strike was necessary.  He could have just given a statement separate from Putin which said something like:
"It is my belief, based on the conclusions drawn by the US intelligence agencies, that Russia engaged in inappropriate actions to meddle in the 2016 US Presidential election.  Although, their actions had no impact on the election's outcome, this is still unacceptable conduct on their part, nevertheless.  I have told President Putin that any such further actions could irreparably damage the ability of our two nations to have mutually beneficial diplomatic relations."  
Now, what would have been wrong with that?  That would have been diplomatic while also holding Russia accountable for their actions.  If he had said something even close to that; he wouldn't be getting eviscerated right now by fellow Republicans.