Thankfully the deterrent of nukes comes from having them and maaaaaybe being willing to use them. It seems to have worked thus far, and until all nations (including places like Iran and North Korea) give them up we will have to be willing to maintain a stockpile.
If other nations have small yield nukes and incorporate them into their war plans then it would probably be smart for us to do so as well. I mean, a nation might be emboldened to use their tactical nukes if they know we can only respond with the big boys. That wouldn’t be “proportional” and thus might be taken off the table.