To understand the thinking of American presidents, historians, contemporaries, and political rivals, have often sought out the texts that most influenced them. George Washington, for example, was known to love Cato: A Tragedy, Joseph Addison’s civics-heavy play about the man who tried and failed to block Caesar’s path to tyranny. He loved the play so much that he forced demoralized troops at Valley Forge to view a staging of it. Calvin Coolidge was apparently so enamored of Cicero that he nearly became fluent in Latin after regularly reading him. Herbert Hoover, who grew up poor and became insanely wealthy, was, unsurprisingly, a big fan of Dickens’ David Copperfield.

For President Donald Trump, one such Rosetta stone seems to be Norman Vincent Peale’s The Power of Positive Thinking. But another key text is an interview he himself gave to Playboy magazine in 1990, when he was but a mere real-estate mogul and New York institution. The interview, at turns eerie and prophetic, runs through his typically immodest self-assessment and catalogues his political philosophies, while offering a scathing appraisal of America, which he saw (and still sees) as “weak” and “pushed around” by the rest of the world. In the interview, he also unfurls a blueprint for his hypothetical presidency, years before winning the White House.

In recent months, at least two world leaders have shared the interview with their staffs in advance of their first meetings with the president. According to The Wall Street Journal, Japanese officials revisited it ahead of Prime Minister Shinzo Abe’s visit last month; German Chancellor Angela Merkel also studied it before arriving in the United States this week, several sources say.

Beyond the standard self-aggrandizement and hagiography of Trump’s own business deals, what makes the Playboy interview instructive reading for foreign eyes is how, with greater depth than many of his campaign soundbites, the future president prioritizes America’s trade partnerships. In response to a question about the first thing a hypothetical President Trump would do, Trump says, “Many things. A toughness of attitude would prevail. I’d throw a tax on every Mercedes-Benz rolling into this country and on all Japanese products, and we’d have wonderful allies again.” With Trump’s long-held passion for taxing German luxury cars likely on Merkel’s mind, then, it’s perhaps unsurprising that  Harald Krueger, the CEO of BMW, was among the German business leaders she brought along on her White House visit on Friday. As Automotive News notes, the German automaker’s largest production factory is in South Carolina. Merkel is keenly interested in whatever plans Trump has for German autos.

One of the more notable recurrent themes in the Playboy interview is Trump’s fixation on Japan, whose economic clout at the time was, in his words, enabled by “openly screwing us.” He laments how U.S. military ships helped safeguard oil shipments traveling from the Persian Gulf to Japan, only to be used to compete against American auto companies. We’re losing hundreds of billions of dollars a year while they laugh at our stupidity,” he says. In the following years, with Japan’s financial standing undercut by a recession and its often-debated “lost decades,” it’s easy to see how present-day Trump has come to view China and Mexico as stand-ins for Japan on matters like free trade and the need for tariffs. Trade deals like NAFTA, despite their mixed results, offer him a more direct way of critiquing American economic policies.

Also reminiscent of current-day Trump is 1990-Trump’s emphasis on American strength in foreign policy. Talking about the Cold War and Iran, Trump lamented that, “Some of our presidents have been incredible jerk-offs,” and reiterated several times that “we need to be tough.”

In classic fashion, Trump also assesses himself, along with Mother Teresa, Jesus Christ, and the Pope, as successful people with “far greater egos than you will ever understand.” The future president transposes the need for this personal ideology into a national imperative and, once again, directs his rage more at America’s friends than its enemies.

I think our country needs more ego, because it is being ripped off so badly by our so-called allies; i.e., Japan, West Germany, Saudi Arabia, South Korea, etc. They have literally outegotized this country, because they rule the greatest money machine ever assembled and it’s sitting on our backs. Their products are better because they have so much subsidy.

We Americans are laughed at around the world for losing a hundred and fifty billion dollars year after year, for defending wealthy nations for nothing, nations that would be wiped off the face of the earth in about fifteen minutes if it weren’t for us. Our “allies” are making billions screwing us.

In other remarks that would echo his language today, Trump explains how a future President Trump would handle military matters. “He would believe very strongly in extreme military strength,” Trump says. “He wouldn’t trust anyone … he wouldn’t trust our allies; he’d have a huge military arsenal, perfect it, understand it. Part of the problem is that we’re defending some of the wealthiest countries in the world for nothing.”

Though it hardly took an old interview to predict it, in Trump’s joint press conference with Merkel on Friday afternoon, he pressed Germany to fulfill its financial commitments to NATO. “Many nations owe vast sums of money from past years, and it is very unfair to the United States,” Trump said. Merkel, for her part, seemed to extract some of what she hoped for—Trump distanced himself from “an isolationist policy” and reiterated his “strong support” for NATO.

Despite the customary characterizations of Trump as the consummate wildcard, the president—then and now—has shown himself to be remarkably consistent, predictable even. Though the tenor and venue of his 1990 interview may be unconventional, a look back at Trump’s own words seems to show that he has a core set of principles to which he is quite committed.