You’re right this will (or should anyway) invite a major international response. But it won’t be attacking our elections.

It’ll be in international politics and economics.
Were I in charge of another nation, I’d immediately end all diplomatic ties with us. Deporting all US embassy/consolate staff and diplomats. Possibly even visa holders. I’d also end whatever exports my nation made to the US. Buying the goods from my nation’s companies myself. If my nations banks had any money of US nationals, it would be frozen.

But that’s just me. We’ll see what they decide to do.