That isn’t actually what the new nuclear-use policy says, but what a nice, very long post, indeed.
Also, response-in-kind means that a chemical or biological attack will be met with a chemical or biological attack. And yes, the US stockpiles those kinds of weapons, too.
This is pure hyperbole.
So ... what DOES it say? link?
Nope. We dismantled our last binary chemical weapons about 15-20 years ago; we've NEVER had biological weapons stockpiled. Bio weapons are slow-acting, unreliable, and create a long-term hostile environment for our own troops; they're more trouble than they're worth. That's why the US has done its bio research for mainly creating countermeasures to any enemy use of such weapons.
—A former NBC officer.