President Donald Trump gave his first speech at the United Nations last week. And as expected, it was a memorable one. In off–the-cuff-remarks that once again provided a memorable reaction from White House Chief of Staff John Kelly, Trump personally insulted Kim Jong Un. In the same breath, the president suggested the North Korean leader was suicidal. Trump also focused heavily on American sovereignty and, even while pledging cooperation with other international actors, he suggested a more unilateral approach to U.S. foreign policy.

The speech garnered a great deal of reaction in its aftermath. Some have suggested that it marked a significant departure in American foreign policy. However, it is worth parsing how much was actually new in Trump’s speech and what its implications were.

Two aspects of Trump’s speech suggest major departures from American foreign policy. First, Trump’s robust assertions about national sovereignty suggested a new unilateral turn in U.S. foreign policy. Second, in the same sentence in which he mocked Kim as “rocket man,” Trump said the United States would “totally destroy” North Korea if the Kim regime attacked a U.S. ally.

Neither the theme of unilateralism nor the threat to annihilate a country for attacking a U.S. ally is really all that new. While America’s pre-World War II foreign policy is often (wrongly) referred to as isolationism, unilateralism more accurately describes it. As historian Walter McDougall wrote in Promised Land, Crusader State: The American Encounter with the World Since 1776, “Let us dispense with [isolationism] altogether and substitute for it a word that really describes the second great tradition in American foreign relations: Unilateralism.”

McDougall continued:

Unilateralism never meant that the United States should, or for that matter could, sequester itself or pursue an ostrich-like policy toward all foreign countries. It simply meant, as Hamilton and Jefferson both underscored, that the self-evident course of the United States was to avoid permanent, entangling alliances and to remain neutral in Europe’s wars except when our Liberty—the first hallowed tradition—was at risk.

Unilateralism as an American foreign policy tradition was not confined to the pre-World War II era. As historian Melvyn Leffler argued in a discussion of former President George W. Bush’s post-Sept.11 unilateralism:

During the Cold War, policymakers adroitly and skillfully formed alliances and held them together, but never foreclosed the right to act unilaterally and often did so. Unilateralism is quintessentially American. And when the Cold War ended, temptations to act unilaterally multiplied, often infuriating allies. [Former President Bill] Clinton sometimes worked assiduously to contain and coopt unilateralist pressures, but he, too, recognized that unilateralism was not only politically expedient, but also might be strategically imperative.

Similarly, the threat to destroy a country in response to an attack on a U.S. ally has been at the heart of America’s extended deterrence strategy dating back to the early days of the nuclear age. In his famous 1954 speech at the Council on Foreign Relations, Secretary of State John Foster Dulles announced that the policy of the United States in response to Soviet aggression against its allies would be one of “massive retaliatory power” using nuclear weapons. While the United States has constantly searched for ways to respond to aggression and maintain the credibility of its extended deterrence guarantees at lower levels of violence, that threat to essentially destroy a country has remained present ever since.

So why was Trump’s speech a problem?

There are three major differences in his speech. First, it is unclear what larger principle the Trump administration’s unilateralism is moored to. Early American unilateralism was a means to avoid entanglement in European great power politics for the preservation of American liberty. Postwar multilateralism was a means to preserving an open international system that American leaders believed would present another World War. Even the Bush administration’s unilateralism—to which some compared Trump’s speech—was moored to a larger principle of spreading liberal democracy and maintaining a liberal international order through robust application of U.S. military power. Throughout his speech Trump’s assertion of the principle of sovereignty was uneven—suggesting possible military interventions in Iran, Venezuela, and elsewhere—because it was unclear what principle unilateralism is meant to serve for the 45th president.

Second, the typical paeans to multilateralism and unwillingness to explicitly threaten to destroy an entire country in retaliation for an attack on America’s allies served a purpose. Some people who do not otherwise support Trump in any way have suggested that his willingness to jettison America’s traditional talk of values and instead embrace naked self-interest as the basis of U.S. foreign policy is a good thing because America never lives up the ideals it claims underpin its foreign policy. However, as political scientists Henry Farrell and Martha Finnemore explained in May, such hypocrisy is useful:

In moderation, Trump’s lack of control might be refreshing. When in a February interview, Fox News’ Bill O’Reilly pressed Trump about his relationship to Russian President Vladimir Putin—“a killer”—Trump responded that there are many killers and asked rhetorically whether “our country was so innocent.” He pointed out aspects of U.S. behavior that both liberals and conservatives prefer to gloss over. Under ordinary circumstances, a presidential acknowledgment that the United States has regularly killed people under sketchy circumstances might spur serious debate. But nothing about Trump is moderate. Trump wants not only to acknowledge America’s dark side but to embrace it, building U.S. policy on naked self-interest and short-term advantage.

 

The problem is that hypocrisy is as crucial to international politics as to personal relations. Blunt pursuit of self-interest is rarely appealing to others. American leaders used to push the self-serving myth that U.S. interests and the world’s interests were mostly the same, and that America was the one indispensable nation. Now, Trump has driven a highly visible wedge between American interests and the world’s. “Make America Great Again” might be an attractive slogan to a many American voters, but it is unlikely to attract non-Americans, who fear that Trump wants to make America and himself great at their expense, something that, in turn, will make greatness harder to achieve.

While it is easy to yawn at platitudes about American ideals most presidents spout as the United States conducts military operations around the globe, the appeals to American beneficence play an important role in producing peaceful international cooperation. They suggest, for all of America’s many flaws, it aspires to something greater even if it, more often than not, fails to achieve it.

Third, whether implied or explicit, threats to destroy an entire country are premised on the idea that the actor on the receiving end is rational and interested in self-preservation. Trump’s declaration that “rocket man is on a suicide mission” suggests that he does not think the North Korean leader is rational.

As Mira Rapp-Hooper, an expert on nuclear deterrence at the Paul Tsai China Center at Yale Law School, noted following Trump’s remarks, the president could be building the case for preventive war. In the process though, he may be raising the risks of miscalculation. She wrote:

If, in fact, it was true that Kim is not able to act in his own self-interest and unable to respond to deterrent threats, that would help to build the case for preventive war against North Korea. In that scenario, it might actually make sense to pay the horrendous costs of a military confrontation to eliminate a far worse nuclear threat—if one believed it was inevitable that North Korea would use nuclear weapons against the United States and its allies later.

 

There is no evidence that this is true of Pyongyang—repeat—no evidence whatsoever. North Korea has long had a stated goal of reunifying the Korean Peninsula, but the country has been deterred from large-scale military action since the end of the Korean War in 1953. The fact that Kim and his father and grandfather before him managed to stay in power despite long odds suggests that they are masters of survival, and therefore rational calculators.

 

[National Security Adviser H.R] McMaster’s argument appears to rest on a false premise: that a brutal, loathsome dictator can’t also be a rational actor. History shows the opposite (take the examples of Joseph Stalin, Mao Zedong). The fact that Trump said Kim “is on a suicide mission” is worrisome. If Trump believes this, it could be part of a justification for preventive war.

Rapp-Hooper continued:

Trump’s characterization of Kim as being “on a suicide mission” may raise the North Korean leader’s fear that Trump shares McMaster’s view: If Kim is undeterrable, then a U.S. first strike may be logical.

 

If Trump is bluffing, he is also raising the risk of miscalculation and an accidental or inadvertent clash. If he is serious, he is threatening preventive military action that could start the bloodiest conflict since World War II.

To sum up: Trump’s rhetoric at the U.N. last week was not much of a departure from America’s foreign policy traditions. However, the fact that it is unmoored from any larger principle and unnecessarily reckless makes it both counterproductive and dangerous.