Concerns about nuclear proliferation, already heightened by the Russian invasion of Ukraine in 2022, have reached a fever pitch in recent weeks, as analysts worry that the Trump administration’s apparent embrace of Russia and distancing from allies could lead some U.S. partners to take their security into their own hands through the acquisition of nuclear weapons.
In recent days, Polish Prime Minister Donald Tusk suggested that his country should consider acquiring nuclear weapons, and the likely next German chancellor, Friedrich Merz, raised the possibility of hosting French or British nuclear weapons as a hedge against the declining credibility of U.S. security guarantees. Meanwhile, South Korean politicians continue to debate the merits of seeking an independent arsenal. Given these trends, how likely is it that we will see a surge of nuclear proliferation?
Concerns about nuclear proliferation, already heightened by the Russian invasion of Ukraine in 2022, have reached a fever pitch in recent weeks, as analysts worry that the Trump administration’s apparent embrace of Russia and distancing from allies could lead some U.S. partners to take their security into their own hands through the acquisition of nuclear weapons.
In recent days, Polish Prime Minister Donald Tusk suggested that his country should consider acquiring nuclear weapons, and the likely next German chancellor, Friedrich Merz, raised the possibility of hosting French or British nuclear weapons as a hedge against the declining credibility of U.S. security guarantees. Meanwhile, South Korean politicians continue to debate the merits of seeking an independent arsenal. Given these trends, how likely is it that we will see a surge of nuclear proliferation?
One way of answering this question is looking to the past. While many aspects of the Trump administration’s behavior and policies are unique, key features of the current landscape have historical echoes. These may give us clues about how proliferation is likely to unfold. As the aphorism goes: History doesn’t repeat itself, but it often rhymes.
In fact, this is not the first time that a U.S. president has sought to substantially reduce America’s alliance burden while seeking accommodation with a major adversary. The Nixon administration attempted a similar pivot by retrenching in Asia and seeking an opening with China.
What can we learn from this period that might hold lessons for nuclear proliferation today? From the standpoint of nonproliferation, there is good news and bad news. The bad news is that President Richard Nixon’s policies did in fact encourage key U.S. allies to seek nuclear weapons. The good news is the nuclear genie was kept in the bottle—but only through the painstaking efforts of Nixon’s successors.
On July 25, 1969, Nixon told reporters that the United States would no longer play the leading role in providing for the conventional defense of its Asian allies. “We must avoid the kind of policy that will make countries in Asia so dependent upon us that we are dragged into conflicts such as the one we have in Vietnam,” Nixon said, adding that the United States “has a right to expect that this problem [of military defense] will be handled by, and responsibility for it taken by, the Asian nations themselves.”
This policy, which became known as the Nixon Doctrine, was not just rhetoric: Nixon withdrew hundreds of thousands of U.S. troops from Vietnam, pulled 20,000 troops from South Korea, and began reducing the U.S. military presence around Taiwan by removing warships from the Taiwan Strait and nuclear weapons that had been stationed on Taiwan and withdrawing troops.
This retrenchment effort was linked to another key foreign-policy priority: seeking an accommodation with Mao Zedong-era China, a bitter Cold War enemy of the United States. Nixon and his national security advisor, Henry Kissinger, believed that such an opening had the potential to shift the Cold War balance of power in their favor, induce the Soviets to behave more cooperatively, reduce the odds of war, and facilitate further U.S. retrenchment from costly defense commitments in Asia.
Unsurprisingly, U.S. allies in Asia viewed these steps with great alarm. While Nixon had not abrogated any alliance treaty and promised to maintain the U.S. nuclear umbrella, confidence in Washington as a protector was badly shaken.
Taiwan, which began laying the groundwork for a nuclear weapons program after China acquired nuclear weapons in 1964, accelerated its nuclear efforts during Nixon’s administration. As a 1972 U.S. intelligence assessment accurately judged, “some on Taiwan may be questioning how long they can count on all-out US support. … Taipei may see such a [nuclear] capability as a potentially useful hedge for the unknown exigencies of the future, when Taiwan may be alone and facing great risks.”
Nixon’s policies spurred South Korea to begin a nuclear weapons program as well. As with Taiwan, the U.S. intelligence community accurately diagnosed the situation. According to a 1978 CIA report: “The importance of the United States in the peninsula’s strategic equation has made Seoul acutely sensitive to what it perceives as any weakening of Washington’s commitment.” South Korea’s concerns, the report continues, “began intensifying after the enunciation of the Nixon Doctrine in 1969. … Sino-American moves toward detente raised further apprehensions in Seoul.”
Ultimately, it fell to Nixon’s successors to prevent Taiwan and South Korea from crossing the nuclear threshold. Whereas the pressure Nixon placed on Taiwan over its nuclear program was relatively minimal—consistent with his disinterest in nonproliferation more broadly—the Ford and Carter administrations put intense pressure on Taiwan to roll back its nuclear weapons program, threatening to cut off military aid and civilian nuclear assistance.
While Taiwan understood that the United States was moving toward normalizing its relations with China and abrogating the U.S.-Taiwan Mutual Defense Treaty, its leaders recognized that they would remain dependent on U.S. arms sales. When Taiwan began secretly exploring nuclear weapons again in the 1980s, the Reagan administration stepped in, coercing Taipei into shutting the program down once again.
The story with South Korea parallels Taiwan. The Ford administration threw the book at South Korea over its nuclear program, going so far as to ask South Korean officials if they were “prepared [to] jeopardize … vital partnership with U.S., not only in [civilian] nuclear and scientific areas but in broad political and security areas,” according to 1975 State Department cable.
South Korea responded by reining in its nuclear program, but when the Carter administration announced a plan to withdraw U.S. ground forces from the peninsula, South Korean officials again began to signal that they might be forced to seek nuclear weapons. Carter ultimately backtracked on the troop withdrawal, but South Korea only definitively ended its nuclear weapons ambitions when the Reagan administration strongly reaffirmed the United States’ commitment to South Korea’s security.
So, what does this all mean for nuclear proliferation today? History suggests that if President Donald Trump follows through on his apparent desire to scale back alliance commitments while seeking detente with key adversaries, some U.S. partners will at least explore the nuclear option. Which countries go down this road would likely depend on which alliances the Trump administration significantly retrenches from. Right now, the focus is on Europe, but during his first term, Trump had acrimonious relations with South Korea as well.
Some might argue that the situation is even more dire today than it was in the 1970s. For example, although Nixon and Trump are similar in intentionally cultivating their reputation for unpredictability, Nixon deployed that strategy primarily against adversaries, whereas for Trump it is omnidirectional. This might make U.S. allies today even more worried than U.S. allies were in the 1970s.
On the other hand, the nonproliferation regime today is also significantly more robust than it was in Nixon’s era, which means it is unlikely that any U.S. ally will take its nuclear decisions lightly. The Trump administration could decide to coercively oppose proliferation by allies even as it scales back alliance commitments, relying on its economic leverage and role as an arms supplier, much as the United States did with Taiwan in the 1970s. The same Trumpian unpredictability that makes allies consider their nuclear options could also make them worry about his response when they do.
These risks could push U.S. allies with nuclear desires to adopt or expand nuclear hedging strategies—that is, developing the technical capabilities that would enable them to build nuclear weapons relatively quickly at a later date—rather than pursuing nuclear weapons outright. Or it could push U.S. allies to seek new extended deterrence relationships, as several NATO countries seem to be exploring with France and Britain.
However, if the Trump administration indicates that it is OK with allies building nuclear weapons, along the lines of comments Trump made during the 2016 campaign, or fully exits from key alliances, it is more likely that some U.S. allies or former allies will aggressively seek nuclear weapons. If this scenario comes to pass, it may fall to Trump’s successors to try to hold the line, just as it did to Nixon’s successors 50 years ago.
The post How Nixon Pushed Allies to Build the Bomb appeared first on Foreign Policy.
