From Theodore Postol at Naked Capitalism:

[Putin] actually signals 2004 as a time where there was a decision made in Russia that you couldn’t talk to the Americans and we’re just going to have to go ahead and build some weapons to make it clear to them that there’s no possible advantage they can gain from missile defenses…

[I]t’s kind of a crazy, thoughtless and dangerous kind of statement to be making that you’re going to use nuclear weapons or any kind of military force in response to a cyber attack unless you claim also that you have the means to determine unambiguously who was responsible for the attack.

So, it shows a kind of reckless attitude on the part of the Department of Defense people and ignorance, or ignorance, or recklessness and ignorance among the people who wrote the Nuclear Policy Review, and I’m afraid that that is evident in a whole bunch of things they say…

I was at the Pentagon working for Chief of Naval Operations. When I look at the situation we have today with the American nuclear arsenal, I don’t know how we’re going to use all these weapons because the number of what you might call targets, Russian ICBMs and command centers, has been reduced substantially because of arms reductions…

This comment from the White House, “We have no missile defenses that work. It’s a joke.” Now, Putin seems to understand that. So, he’s not afraid that we have a working missile defense. He’s afraid we might think we have a working missile defense because our political leadership is so out of touch with the realities of our own military capabilities and limitations…

What they have said is, “Look, you have these ballistic missile launch sites that you’re putting in. You have one in Poland and one in Romania.” Now, these ballistic missile launch sites, they’re defensive, supposedly ballistic missile defense systems, they are derived, they’re land based but they’re derived from a sea-launched system. They’re called vertical box launchers. A typical destroyer or a cruiser, a modern cruiser or destroyer has them…

[T]hey can carry nuclear armed cruise missiles, sea launched cruise missiles that would be launched from these ground locations.

From the comments:

It’s a matter of time. When the available nuclear weapons delivery systems were based offshore in the sea, or on landmasses thousands of miles away, the ‘actors’ here had a limited but discrete amount of time to make up their minds whether or not to launch a retaliatory strike. Time was available for the launch controller from the Duchy of Grand Fenwick to call up the launch controller of Freedonia and yell: “It’s a mistake! Don’t shoot! We’re disarming the warhead now! We owe you lunch!”

With the missile launch systems now right on the Russian border, no such time buffer exists any longer.