You're so wrong on so many levels I hardly know where to start. I guess first would be your continual attacks on the US and presuming to know our intent is solely imperial. That you would go so far as to include a US first strike in your "logic" is about as absurd as it gets. If we wanted to kick Russia's ass it'd already have been done, and if we were going to use the nukes we'd have done so long ago.
A key hole in your theory is that it would benefit the US in NO way to do so.
The fact you try to justify the actions of a nation that has been nothing but hostile to every other nation it has ever come in contact with for at least the past millenia is even MORE ridiculous.
And quite simply, if we, the US, are doing something that benefits the US and its allies, screw what the detractors have to say. With Putin being the nimrod with his finger on the button of whatever remaining nukes Russia hasn't sold on the black market or is giving away for free to religious idiots that have no problem with annihilating the entire world if it doesn't bow to them, I'd want a defensive missile system too.