On Factba.se, an invaluable compendium of Trump’s interviews, public remarks, tweets, and more, the first mention of Iran and hostages comes in an October 1980 interview with the journalist Rona Barrett. “It should really be a country that gets the respect of other countries,” Trump says. He goes on:

Trump: When you get the respect of the other countries, then the other countries tend to do a little bit as you do, and you can create the right attitudes. The Iranian situation is a case in point. That they hold our hostages is just absolutely, and totally ridiculous. That this country sits back and allows a country such as Iran to hold our hostages, to my way of thinking, is a horror, and I don’t think they’d do it with other countries. I honestly don’t think they’d do it with other countries. Barrett: Obviously you’re advocating that we should have gone in there with troops, et cetera, and brought our boys out like Vietnam. Trump: I absolutely feel that, yes. I don’t think there’s any question, and there is no question in my mind. I think right now we’d be an oil-rich nation, and I believe that we should have done it, and I’m very disappointed that we didn’t do it, and I don’t think anybody would have held us in abeyance. I don’t think anybody would have been angry with us, and we had every right to do it at the time. I think we’ve lost the opportunity.

(Amusingly, when Barrett asked Trump, a famous draft dodger, whether he would have wanted to be part of the team that went in, he replied, “I wouldn’t have wanted to be, but I would have done it.” He also demurred when she asked whether he’d want to run for president, because TV had ruined the process: “Abraham Lincoln would probably not be electable today because of television.”)

Here we can see the essential ingredients of Trump’s approach to Iran and the Middle East today: an obsession with respect, especially perceived disrespect; an impulse toward quick, short military action; the desire to take oil; and a focus on the hostage crisis. These have persisted ever since.

In 2010, as Trump was restarting his political career (and campaigning against an Islamic center in lower Manhattan), he told ABC’s George Stephanopoulos, “I’ll never forget when Iran had the hostages. And Jimmy Carter was helpless. It was just sad. And Ronald Reagan came in and he said those hostages will be delivered immediately. They were let go. They were let go. It was respect. We don’t have respect from the rest of the world.”

The following year, he said something similar to Steve Forbes:

People forget Iran. They had our hostages, and Jimmy Carter was the president, and it was pathetic. We’d still have those hostages there today, if a Jimmy Carter were still president. And Ronald Reagan said something to the effect that, ‘They won’t be there one day, if I’m president.’ As soon as he was elected, amazingly, the hostages were released. It was amazing, right? But it wasn’t amazing to me. And he meant it. He wasn’t playing games, he meant it … Had Jimmy Carter won that election—would’ve been a very sad day for the country, for a lot of other reasons—but that whole hostage situation. We had respect. We were respected as a nation.

Two years later, he tweeted:

US froze $8B in Iranian assets during ’79 Hostage Crisis. Now Obama is giving it back to Iran while Christian Pastor is jailed. Don’t do it! — Donald J. Trump (@realDonaldTrump) November 27, 2013

The consistency of Trump’s views on Iran is remarkable because his positions on practically everything else (the Iraq War, his party affiliation, abortion, health care) have shifted, sometimes repeatedly, over the years. But the issues on which he has been consistent are those, like trade protectionism and immigration, on which his views were forged in the ’70s and early ’80s, when Trump was a young man. These are also the issues on which he has been most persistent as president—and most impervious to persuasion or new information.