It was March 1 and Vladimir Putin was feeling invincible.

Russian advancements in intercontinental ballistic missile modernization, maneuverable-trajectory hypersonic missiles, and even a nuclear-fueled cruise missile carrying a nuclear payload, the Russian president boasted, would make short work of America’s antiballistic missile defenses. In case there was any ambiguity to Putin’s fiery Kremlin address, Putin underscored his point—Russia can hold any U.S. city at risk in the event of a conflict—with an animated video showing a Sarmat missile strike on Florida, home of Donald Trump’s cherished Mar-a-Lago resort.

“Sarmat is a very powerful, mighty weapon,” Putin said. “Due to its characteristics, nothing, not even prospective antiballistic missile systems could be an obstacle for it.”

Putin’s speech followed on the heels of two Trump administration steps with significant implications for the nuclear balance of terror. In December, the administration released a strategy document, the brainchild of national security adviser H.R. McMaster, that embraced a return to “great-power competition” between Washington and Moscow.

To back it up, in February, the Pentagon’s Nuclear Posture Review committed the U.S. to expanding the “flexibility and range” of its own nuclear weapons (PDF), at the cost of over $1 trillion, and including the development of a “low yield” nuke that arms control experts fear will tempt policymakers into using it.

But Putin was not responding to anything Trump had done. He wasn’t even responding to anything Barack Obama had done. The revived buildup of apocalyptic weaponry began, in Putin’s eyes, a decade and a half earlier, with a fateful decision by George W. Bush’s administration: to back out of the seminal arms control pact known as the Anti-Ballistic Missile, or ABM, Treaty.

“If you were to speak about ‘arms race,’” Putin told NBC’s Megan Kelly, “then an arms race began at exactly the time and moment when the U.S. opted out of the Anti-Missile Treaty.”

Putin’s March 1 speech spoke bitterly of shadowy forces who have tried to “escalate the arms race for the past 15 years.” (Never mind the arms-limitation treaties he signed with Bush in 2002 and Obama in 2010.) Russia’s maturing nuclear arsenal, Putin boasted, was the fruit of Washington’s ABM folly: “You didn’t listen to our country then. Listen to us now.”

It is unlikely the Trump administration will listen—especially now that McMaster is being supplanted as national security adviser by John Bolton. As Bush’s undersecretary of state for arms control, Bolton was the State Department’s principal advocate of tearing up the ABM Treaty—and, as an envoy to Moscow over the arrangement, was the one who ripped it up in the Kremlin’s face.

Since Bolton’s elevation to national security adviser, much has been made of his bellicose statements toward North Korea and Iran, his continued defense of the disastrous Iraq War, and his much-vocalized contempt for arms-reduction agreements, particularly the 2015 Iran deal. Far less attention has gone to his role in getting rid of the Anti-Ballistic Missile Treaty—a footnote buried in the accumulated foreign-policy wreckage of the Bush administration, but one bitterly remembered in Moscow, where it contributed to the present reemergence of U.S.-Russia antagonism.

Bolton was hardly alone in counseling the end of the ABM Treaty. Vice President Dick Cheney, Secretary of Defense Donald Rumsfeld, National Security Council staffer Robert Joseph were key actors, and the Reagan era elevated missile defense into right-wing catechism. Bolton added his particularly pugilistic style. He mocked what he called the “Church of Arms Control” the year before taking office as the State Department’s top arms-control official.

“When we cancelled the ABM Treaty, we did two things,” said Jim Walsh, a nuclear-strategy scholar at the Massachusetts Institute of Technology. “We embarrassed Russia, we left them hanging. That’s a psychological effect, but there was also a direct consequence for their national security: If we build a missile defense, the only way they can respond is to build new missiles. That’s why we had an ABM Treaty in the first place, because we knew missile defense leads to arms races and creates strategic instability.

“John Bolton is politically and culturally at the center of that,” Walsh continued. “He believes in weapons over diplomacy, and coercion over negotiation. Whether it’s being pro-missile defense, pro-regime change, or anti-UN, the record there has been a remarkably consistent one.”

Bush came into the White House determined to build a ballistic missile shield. But with the Cold War over and missile threats from Iran, Iraq, and North Korea at the fore of his mind, Bush didn’t consider that Russia would truly care about getting rid of the 1972 ABM Treaty, the obstacle to his plans. Instead, Bush appeared to convince himself that the Cold War vestige was actually an obstacle to improved relations with Putin. “It’s a piece of paper that’s codified a relationship that no longer exists. It codified a hateful relationship. And now we’ve got a friendly relationship,” Bush said during Putin’s November 2001 visit to the White House.

Putin, standing beside Bush, was substantially less enthusiastic. “On the issues of missile defense,” Putin rejoindered, “the position of Russia remains unchanged.”

But there was little Putin could do about it. In 2001, Russian power was still mired in its post-Soviet nadir. Moscow seethed impotently at the ABM withdrawal. In talks with U.S. diplomats throughout the year, largely with Bolton taking the American lead, Russian officials said getting out of the deal would undermine “the entire framework of international security.”

Moscow took multiple approaches to underscore its dissatisfaction. It threatened an arms race. It rejected a Washington entreaty to tear up the treaty bilaterally, and offered instead to modify the treaty in a manner that might satisfy Washington—which the U.S., through Bolton, rejected. It back-burnered opposition after the 9/11 attacks in the hope Bush would do the same. But the brutal truth was that the Kremlin was in little position to do anything but acquiesce.

Bolton was the point man for ABM Treaty diplomacy with the Russians—itself a signal that there was no doubting Bush’s intention to get out. Bolton even went to Moscow the week after the 9/11 attacks to underscore the point, and felt nothing of wrapping a U.S. missile shield in the bloody shirt of a terrorist attack that the shield would never have stopped.

“While missile defense would not have prevented this abomination,” Bolton said at the time, “it does show that the United States faces severe threats from terrorism and from rogue states, and that among the things we have to continue to work on is missile defense.”

Bolton’s offer to Moscow was Corleone-esque: nothing. An anonymous U.S. official told The Washington Post’s Russia correspondent, during a Bolton sojourn to the Kremlin, that the Russians “realized that maybe we’re not going to negotiate on this before the treaty is gone.”

Bolton would soon gloat—on the record—that he had gotten the Russians to recognize that U.S. withdrawal from the treaty was an uncomfortable pill they nevertheless needed to swallow. “I tried to convince the Russians when I was in Moscow last week how serious we are about withdrawing from this treaty,” Bolton remarked. “I said: ‘You need to start understanding this treaty as a six-month treaty, renewable on a daily basis.’ And I think that got their attention.”

The Bush administration permitted Putin to save a modicum of face. Bush, in May 2002, committed to reducing the U.S. nuclear stockpile. Once again it was Bolton who negotiated the details with the Russian deputy foreign minister—after Putin insisted on a formal agreement—and once again it was Bolton who underscored Washington’s red lines. Among Bolton’s priorities during negotiations, he said, was not “starting a process that limits our national missile defense.”

America could do as it liked at the time of its ABM withdrawal. It was the height of its post-Soviet unipolar advantage: Not only did the U.S. enjoy the world’s sympathy after 9/11, it had yet to squander its diplomatic and military power with the Iraq invasion. “There was Bolton, taking advantage of a moment of Russian relative weakness,” said Thomas Countryman, a longtime U.S. diplomat who worked on arms control, and who the Trump administration pushed out last year.

Usually, taking advantage of a rival’s weakness is par for the diplomatic course. But nuclear strategy is maddening. It turns conventional military strategy on its head in a deeply emotionally unsatisfying manner. Conventionally, defenses aren’t just desirable, but unquestionably necessary. But in a nuclear context, a successful missile defense system is provocative, “because people worry if they have a stable deterrent against their adversary,” Walsh explains.

Conventionally, a wise nation wishes to instill confusion amongst the enemy. But in a nuclear context, confusion is destabilizing and can inadvertently provoke a nuclear exchange. Trump’s favorite general, Douglas MacArthur, famously remarked that there is no substitute for victory. But in a nuclear war, victory means annihilation, and the mark of success is stability—stability shared with adversaries we often hate.

Russia’s fixation on U.S. missile defenses may seem to Americans exotic, irrational, or pretextual. Putin is certainly no stranger to cynical manipulations of the factual record when seeking Russian advantage. But Austin Long of the Rand Corporation recently observed in a War on the Rocks essay that Russia’s World War II and Cold War experience created an “abiding fear and respect for U.S. nuclear and missile defense capabilities” leading to Putin’s March 1 nuclear modernization display. The ABM Treaty was born out of reasonable Soviet fears of the more-capable U.S. nuclear arsenal; so it was “better that neither side have missile defenses than the United States be superior in offense and defense.”

By the Reagan era, Long continues, “the Soviet leadership, fearful of renewed missile defense competition and U.S. nuclear modernization, began to mull exactly the sort of systems Putin revealed this month. They did so not because they were crazy, but because they were deeply fearful that the United States would resume missile defense competition in parallel with a competition over the quality of strategic nuclear forces.”

Trump’s Nuclear Posture Review suggests that those Russian concerns remain salient. Countryman, the former State Department official, notes that unlike the document’s Obama-era predecessor, February’s version neglected to include a line assuring Russia that U.S. missile defenses are not intended to undermine the Russian nuclear deterrent, “and I expect the Russians will read something into that admission.” Better, then, from Putin’s perspective, for Russia to declare that its missile development has advanced to a point that renders futile America’s continued focus on a missile shield.

“While I think the Russian concerns are far-fetched—I do not have the same confidence in missile defense and its effectiveness—these are real concerns for the Russians, or at least they have convinced themselves they’re real. And it’s led them to the kind of programs to defeat missile defense that Mr. Putin announced on March 1,” Countryman said.

Sixteen years after the death of the ABM Treaty, there is only the thinnest of U.S. antiballistic missile shields—44 ground-based interceptors of uncertain reliability, along with the Navy’s ship-borne Aegis system—as its technical complexity remains extraordinary. The latest interceptor test, conducted off Hawaii, failed in late January, much as its predecessor did. Regardless, the tragic irony of missile defense in a strategic context is that the more successful U.S. interceptors become, the more destabilizing the Russians will consider them.

But missile shield advocates nevertheless convinced themselves that withdrawing from the ABM Treaty was an unqualified victory—a perspective that implies future arms-control abrogations will encounter no reprisal. When Joseph left the Bush administration in 2007, he remarked: “No one even thinks about the ABM Treaty anymore, which is a true measure of [withdrawal’s] success.”

Another Bush-team arms control official, John Rood, gloated at a 2013 Heritage Foundation forum that he still had a New York Times editorial from the ABM Treaty withdrawal era warning of an invitation to an arms race: “Apparently the invitation got lost in the mail on the way to whoever the recipients were to be.”

Putin’s March 1 announcement, however, underscores that the Russians merely respond at a time of their choosing. “America,” influential parliamentarian Alexei Arbatov remarked to The Washington Post in August 2002, “has gotten used to taking Russia for nothing.” Today, with Russians fielded in Syria, occupying Ukraine and disrupting U.S. political discourse, America is no longer taking Russia for nothing.

The legacy of the ABM Treaty withdrawal, and the conservative misapprehension of its consequences, suggests to Walsh and Countryman that Bolton will encourage Trump to rip up more arms-control deals. That starts with the Iran deal in May—and perhaps accordingly precludes a pact with North Korea, despite the anticipated Trump-Kim summit—but doesn’t end there. Getting rid of the Reagan-era Intermediate Nuclear Forces Treaty may be on Bolton’s agenda, both Walsh and Countryman fear. The treaty limits missiles with a range of 300 to 3500 miles, disproportionately constraining the Russian arsenal, and last year, the vice chairman of the Joint Chiefs of Staff testified that Russia has violated it.

“The U.S. has a choice here,” Walsh added, “sit down with the Russians and try to negotiate it out, or simply wave a wand and say we’re not gonna put up with this, you’re in violation and we’re pulling out.” Observes Countryman: “To get us to take the blame more than Russia [by withdrawing] would be a public-relations coup for them.”

Trump appears inclined to slip into that mode. NBC reported Thursday night that during Trump’s recent congratulatory phone call to Putin, Trump blustered, “If you want to have an arms race we can do that, but I’ll win.”

For Countryman, the ABM Treaty episode is only one critical case in which Bolton was proven “spectacularly wrong” on his area of ostensible expertise.

The Iraq War he championed was a debacle whose consequences included squandering American military power and expanding Iran’s hold over the Middle East. Bolton greeted North Korea’s violation of the 1994 Agreed Framework by rejecting negotiations; now North Korea is a nuclear power. Then Bolton refused “to negotiate except on unacceptable terms” with an Iran that had a mere few dozen centrifuges, rather than the several thousand that spurred the 2015 Iran deal Bolton wants to end.

With so much riding on a peaceful diplomatic resolution of so many pivotal nuclear and missile threats, Countryman said, Bolton is “the last man you should trust.”