We’re four weeks away from Donald Trump’s inauguration as president, and he’s already exchanging boasts and banters with Vladimir Putin over the size of their nuclear arsenals. Should we be alarmed?

It all began Dec. 22, at 8:50 AM, when Trump tweeted the following:

The United States must greatly strengthen and expand its nuclear capability until such time as the world comes to its senses regarding nukes — Donald J. Trump (@realDonaldTrump) December 22, 2016

His aides hemmed, hawed, and backpedaled, as they often do in the aftermath of these posts, saying that the president-elect “was referring to the threat of nuclear proliferation and the critical need to prevent it—particularly to and among terrorist organizations and unstable and rogue regimes.”

But as the clock ticked, some speculated that Trump’s tweet may have been a response to a remark that Putin made in the middle of his annual holiday three-hour press conference—namely, that Russia would bolster its nuclear capability to “penetrate” any enemy’s missile-defense system.

This was confirmed Friday morning by Mika Brzezinski, co-host of MSNBC’s Morning Joe, who reported that she’d spoken on the phone with Trump a while earlier and that he stood by the tweet.* If Putin wants to up his nuclear arsenal, Trump told her, “Let it be an arms race because we will outmatch them at every pass and outlast them all.”

How much of this is mere bluster? How much of it bodes a return to the days of Dr. Strangelove? (“Make America Great Again” indeed!) It’s hard to say at this point. Meanwhile, let’s put the fuss in some context.

First, Putin’s remarks were nothing at all new. Ever since 2001, when President George W. Bush abrogated the 30-year-old Anti-Ballistic-Missile Treaty in order to build an array of missile-defense systems that could (theoretically) protect the United States from a nuclear attack, Russian leaders have said they would counter any such effort with new offensive missiles capable of saturating or evading the defenses.

The reasoning comes straight out of Nuclear Strategy 101. The United States and Russia have long been deterred from launching a nuclear attack by the prospect that the other side would retaliate in kind—hence the phrase “mutual assured destruction.” But if, say, we had a superweapon that could shoot down Russia’s missiles as they plunged to their targets, then an American president might launch an attack, believing that Russia’s counterstriking missiles would be intercepted—hence Russia could not retaliate in kind, hence the United States would “win” the war. To preempt this scenario, Russia could simply build more offensive missiles, thus saturating the American interceptors, or it could design missiles that could maneuver around the defenses. By this logic, the deployment of defensive weapons could spur an endless offensive arms race. Richard Nixon and Leonid Brezhnev signed the ABM Treaty in 1972, banning certain kinds of anti-missile missiles, precisely to ward off this fate.

President Obama changed Bush’s missile-defense program, shifting it away from the goal of shooting down Russian missiles over America (which was deemed infeasible)—and toward the goal of shooting down short- to medium-range Iranian or other roguepowers’ missiles over Europe. In fact, the interceptors that Obama has placed in Poland and on certain naval vessels lack the range or the altitude to intercept Russian missiles. Even if they did have that power, there aren’t enough of them to do much damage. Still, Putin fears encirclement—or says he does—and occasionally sharpens his rhetoric accordingly.

So let’s look at Trump’s tweet. Like most of his tweets, it was probably dashed off with no care to nuance, but let’s do what his aides have told us not to do and read it “literally and seriously.” What does it mean to “greatly strengthen and expand” our “nuclear capability”? It might mean building more missiles or more destructive warheads. Or it might simply mean making our arsenal more reliable, more “capable”—maintaining the nuclear labs, upgrading certain components, and, improving the command-control links, so that, if a president did someday push the button, the missiles would actually launch, arc through outer space, re-enter the atmosphere, and explode over their intended targets.

If Trump meant the latter, President Obama is doing this already with a nuclear “modernization” plan costing roughly $35 billion a year. In addition to all the maintenance work described above, this plan envisions the gradual deployment of new land-based intercontinental ballistic missiles (ICBMs), new submarine-launched ballistic missiles (SLBMs) and the submarines that carry them, new bombers, and new air-launched cruise missiles (ALCMs). These weapons are in the early stages of development; they couldn’t be ready for deployment until the late 2020s or early 2030s. Meanwhile, it’s worth noting that, for the past few years, the Russians have been replacing old ICBMs with new, more destructive ones. The United States some time ago got rid of all its ICBMs that carry multiple warheads; Russia still has quite a few.

Totaling up each side’s “strategic” arsenal, i.e., the number of warheads and bombs that could strike the other side’s territory, the United States has 2,070 weapons (with another 2,508 in storage), while Russia has about 2,600 weapons (with another 2,400 in storage).

First, some historical perspective. At its peak, in 1967, the U.S. nuclear arsenal totaled more than 30,000 weapons. (This included a lot of bombs, short-range missiles, and even nuclear artillery shells in Western Europe and South Korea, all of which have since been dismantled.) Even in 1991, at the end of the Cold War, we had 19,000. The arsenals on both sides have come way down.

But second, Russia has about 500 more nuclear weapons than we do. Does this mean that the Russians are, in any meaningful way, “ahead”? No. The only measure of strength in the nuclear realm is this: If an enemy launched a nuclear first-strike, would the nation under attack have the weapons, the technical ability, and the will to launch a counterattack that inflicts devastating damage? If the answer is yes, then it doesn’t matter how many weapons either side has—or whether one has more than the other.

This measure is vague on the definition of “devastating damage” and on how many nuclear weapons are needed to inflict it. But by any measure, 2,000 are more than enough. For instance, China has about 180 nuclear weapons, and its leaders seem to think that’s enough to deter Russia, the United States, or some other adversary from entertaining the notion of launching an attack or an invasion.

Each of these weapons has a designated target (there are officers at U.S. Strategic Command who do nothing but assign weapons to targets in myriad scenarios and war plans), but a lot of these targets are the nuclear complexes (missile silos, submarine pens, and bomber bases) on the other side. The idea that the leaders of the United States, Russia, China, North Korea or whatever other country would launch dozens, much less hundreds or thousands of nuclear weapons against another country, without inciting a retaliatory attack—and the idea that any of these leaders would accept the blow of this retaliatory attack as an acceptable price of military “victory”—is simply insane.

Hiroshima and Nagasaki were each wiped out with a single atomic bomb carrying one-tenth the explosive power of the smallest bombs in the American and Russian nuclear arsenals today.

So when Trump talks of strengthening and expanding our nuclear capability, what does he mean? For that matter, when Obama spends billions to modernize the nuclear arsenal right now, what is that for and how much is enough?

And what does Trump mean when he says the United States must do this “until such time as the world comes to its senses regarding nukes”? He could mean that nukes are crazy, the world needs to realize that someday, but until it does, we need to stay strong, we need to maintain the ability to deter an attack. If that’s what he means, well, that’s not so different from what a lot of other presidents, including Obama, have said.

What about Trump’s statement to Mika Brzezinski Friday morning? “Let it be an arms race,” he said, in apparent (and probably overheated) response to Putin’s remark, “because we will outmatch them at every pass and outlast them all.”

First, it’s interesting—perhaps more interesting than anything else in this exchange—that, for the first time, Trump is pushing back against his apparent ally-in-waiting, Putin. Second, in that context, it may be a half-good thing that Trump is pushing back. It may be a half-good thing for the American president-elect to tell the Russians, in effect, “You want an arms race? Remember what happened the last time we had one of those? We can race you into bankruptcy without breaking a sweat.”

I say it may be a “half-good” thing because it would have been better, had Trump followed that remark with something like this: “So let’s stop talking about building more nuclear weapons, which neither of us needs, and talk about getting rid of still more. That’s what I meant by ‘the world coming to its senses regarding nukes.’”

Is there half a chance that Trump, like Ronald Reagan, turns out to be, or somehow evolves into, a closet nuclear abolitionist? Probably not, but he’s given us so much cause for anxiety and despair on so many other grounds, it’s worth at least half a hope. Merry Christmas and Happy New Year!

*Correction, Dec. 27, 2016: This article originally misspelled Mika Brzezinski’s first name. (Return.)