Jessica T. Matthews reviews Henry Kissinger's World Order and Bret Stephens America in Retreat: The New Isolationism and the Coming Social Disorder in the New York Review of Books' current issue. She writes

"[Stephens] also makes the serious charge that Russia has achieved “nuclear superiority over the United States via the [Obama administration’s] New START Treaty.” He does not acknowledge that today the US has many more deployed strategic launch vehicles than Russia, and that the two sides have equal numbers of warheads and launchers (including those not deployed). Moreover, the US arsenal is much more able to survive an attack than Russia’s and is almost certainly far more lethal. His claim is baseless."

That is a serious charge so I decided to look it up. According to armscontrol.org:

"Russia: According to the September 2014 New START numbers, Russia has 1,643 strategic warheads deployed on 528 ICBMs, SLBMs, and strategic bombers. The Federation of American Scientists estimates Russia has several thousand nondeployed strategic warheads and approximately 2,000 tactical nuclear warheads. An additional 3,700 are awaiting dismantlement."

"United States: According to the September 2014 New START declaration, the United States has 1,642 strategic nuclear warheads deployed on 794 ICBMs, SLBMs, and strategic bombers [1].  The Federation of American Scientists estimates that the United States' nondeployed strategic arsenal is approximately 2,800 warheads and the U.S. tactical nuclear arsenal numbers 500 warheads. In total, the U.S. has about 4,800 nuclear warheads [2], including tactical, strategic, and nondeployed weapons. Additional warheads are retired and await dismantlement."

So, Matthews: US "has many more deployed strategic launch vehicles."

      armscontrol.org: Russia has 528 to the US's 794...I'm going to take the rest of those sentences to be the equivalent of Matthews' "strategic launch vehicles." 

Advantage Matthews.

Matt: "the two sides have equal numbers of warheads and launchers (including those not deployed)."

arms: "Russia has several thousand nondeployed strategic warheads and approximately 2,000 tactical nuclear warheads. An additional 3,700 are awaiting dismantlement;" the US "nondeployed strategic arsenal is approximately 2,800 warheads and the U.S. tactical nuclear arsenal numbers 500 warheads. In total, the U.S. has about 4,800 nuclear warheads."

Merriam-Webster: "several-more than two but not very many." 

We'll give Russia 1,643+3,000 +2000 tacs=6,643. We're not going to include the number awaiting dismantlement. The US: 1,642+2,800+500=4,942 OR "about 4,800."

Either way, and giving Russia the lowest number possible within the meaning of "several," Russia has got at least 6,643 to the US' 4,800. In common understanding of "superiority" that is "nuclear superiority" but I think superiority has a different meaning in "nuclear superiority"--I may be wrong!--but I think "nuclear superiority" refers in some way to ability to withstand a first strike. I believe that is why Matt says the US arsenal is "much more able to survive an attack." Now, what Matt means by US nukes also being "almost certainly far more lethal" is nonsensical. 

Jessica T. Matthews writes nothing justifying her dismissal of Bret Stephens' claim that Russia has achieved nuclear superiority with "His claim is baseless."

Advantage Stephens. Game, set and match to Stephens.