U.S. steps up intel, surveillance after Putin's nuke threats

[MarineCombatEngineer]

4. Probably not nukes,

but targeted precision strikes against Russian assets like ADF, troop concentrations, etc,
let's face it, US/NATO forces far outmatch Russian forces in equipment, command and control, training, etc.

Putin would rue the day if he used tactical nukes in Ukr, he would lose any support he might have had from China, India and just about the whole world.