What does it mean for the president of the United States to proclaim that he is a “nationalist”? Donald Trump has identified himself with the most potent  — and the most amorphous — political movement of the past two centuries.

The idea that everyone’s primary allegiance should belong to a nation-state is a relatively recent phenomenon. Until the 20th century, multinational empires were the dominant political units. Nationalism was a product of the 18th-century Enlightenment and initially was associated with other Enlightenment ideas such as the “liberty, equality, fraternity” of the French Revolution and the “life, liberty, and the pursuit of happiness” of the American Revolution. The great nationalists of the 19th century were freedom fighters such as Simón Bolívar, Giuseppe Garibaldi and Louis Kossuth, who sought to liberate their people from the despotism of absolute monarchs such as the Habsburgs and Bourbons.

But nationalism also became associated with terrorists such as the Irish Fenians, who in 1882 murdered two of Britain’s chief officials in Ireland, and the Serbian Black Hand, which was behind the murder of Austrian Archduke Franz Ferdinand in 1914. By the late 19th century, nationalism was being harnessed by conservatives such as Otto von Bismarck and Camillo Benso, the Count of Cavour – the architects, respectively, of unified Germany and Italy. Nationalism’s reputation was permanently stained by the outbreak of World War I – a conflict that was widely blamed on enflamed nationalist passions. Yet the war also gave a substantial impetus to nationalism by triggering the breakup of the Ottoman, Romanov, Hohenzollern and Habsburg empires and the creation of new states from Eastern Europe to the Middle East.

The two decades after World War I saw the rise of the most virulent nationalist movements in history – the Nazis in Germany, the fascists in Italy, and the militarists in Japan. It was this dark period that led George Orwell to describe nationalism as “the habit of assuming that human beings can be classified like insects and that whole blocks of millions … of people can be confidently labeled ‘good’ or ‘bad.’ ” Both Orwell and Charles De Gaulle famously differentiated nationalism from patriotism, with the latter saying: “Patriotism is when love of your own people comes first; nationalism, when hate of people other than your own comes first.”

The Second World War, like the first, was caused by nationalism and gave rise to more nationalism in its aftermath. After 1945, the European empires disintegrated, producing nationalist leaders across Asia and Africa such as Ho Chi Minh, Kim Il Sung, Syngman Rhee, Sukarno, Mao Zedong, Mohammad Ali Jinnah, Jawaharlal Nehru, Gamal Abdel Nasser, Jomo Kenyatta, Kwame Nkrumah and Julius Nyerere. With very few exceptions, such as Lee Kuan Yew, most of these men were brutal and corrupt – and in many cases they oppressed their own citizens even more than their old imperial overlords had done.

Nationalism has gotten such a bad reputation in the West that few U.S. politicians have been willing to associate themselves with the term. One of the few exceptions was Theodore Roosevelt, who chose to call his 1912 campaign platform the “New Nationalism.” But this was simply his catchy label for a progressive agenda that included greater regulation of business and a social security system. It wasn’t proto-fascism.

The word “nationalism” in modern America has often been preceded by a troubling adjective: “white.” Troubling, that is, if you believe in America as a multicultural democracy bound together by shared ideals, not by shared blood. Trump insists that his evocation of nationalism is not a code word for “white supremacy.” “No, I never heard that theory about being a nationalist,” Trump told reporters. He insisted that he is simply “somebody that loves our country.” But if that’s the case, why didn’t he just say so? Trump gave the game away at a Houston rally where he admitted, “We’re not supposed to use that word,” suggesting he knows exactly how toxic nationalism has become in the modern world.

Significantly, Trump preceded his declaration of nationalism with one of his trademark rants against “globalists” – “A globalist is a person that wants the globe to do well, frankly not caring about our country so much,” he said. Who are these villains who want America to suffer? Trump didn’t name anyone, but it’s a safe bet that he has in mind someone like George Soros, a Jewish billionaire who Trump supporters blame for everything from the caravan of Central American immigrants to the anti-Kavanaugh demonstrations. You know who else engages in this kind of anti-Semitic conspiracy-mongering? Trump’s fellow nationalists: Vladimir Putin, Viktor Orban, and the Law and Justice Party in Poland. Like Trump, they also revile the press as the “enemies of the people.”

Trump’s denials of ill intent are simply not credible. They are a convenient ruse allowing him to rouse his base while maintaining semi-plausible deniability. Trump’s followers are in on the joke. They are thrilled by his “politically incorrect” language – code words for racism, misogyny and xenophobia – while publicly denying that he engages in racism, misogyny or xenophobia. Of the two variants of nationalism – liberal and illiberal – there is no doubt which one Trump is evoking. As demonstrated by the bombs sent by some fanatic to Soros, the Clintons, CNN and other targets of Trump’s rhetorical assaults, he is literally playing with fire.

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