[jwtadvice]

Right, you've just reaffirmed what the parent poster said.

The US reserves the right to use it's nuclear weapons in this way. But in no way is this the unique, most important, or most manifest reservation of nuclear force. Nor is the US bound by policy that it will respond to WMDs this way.

This passage says "We don't rule it out."

It's not accurate to round that up to a representation of policy. The parent responded to this characterization quite well.