The U.S. presidential election will probably not hinge on foreign policy. It will hinge on domestic policy—what to do about immigration, for example. It will also hinge on the public’s assessment of the two major nominees, personally. But U.S. foreign policy is always important. So let’s have a look.

Hillary Clinton and Donald Trump are virtually the most famous people in America. But one has a long record in government while the other has none. Mrs. Clinton was First Lady for eight years, Senator for another eight years, and Secretary of State for four. She is a very known commodity.

Yet there is a debate about her, certainly among conservatives: Is she a left-winger or more like a Democratic centrist, à la Madeleine Albright (one of Bill Clinton’s secretaries of state)? It is true that she was one of the left-most figures of her husband’s administration. It is also true that, as a law student, she clerked for Robert Treuhaft, the communist lawyer who was married to a Mitford (Jessica).

But there are plenty of people in American politics to the left of her. One is Senator Bernie Sanders, who was Mrs. Clinton’s rival in the recent Democratic primaries. In one debate, they clashed on Cuba. Mr. Sanders is a great admirer of the Castro dictatorship; Mrs. Clinton pointed out the tyranny of that regime.

I believe that a Hillary Clinton presidency would amount to an extension of Barack Obama’s—in both domestic and foreign policy. I believe she would be a manager of American decline, a decline that she both accepts and, to a degree, welcomes.

Donald Trump is a wild card: volatile, untested, erratic. We know that he is anti-trade. Like most people who are anti-trade, he denies it: he says he is for “fair trade.” But he gives every indication of being an all-out protectionist.

His abiding theme, other than himself, is strength: strength in all things, at home and abroad. This is a strength that often comes off as belligerence. When it comes to the War on Terror, a great many will excuse him.

He says that he would “bomb the shit” out of ISIS. He would not send many ground troops to the Middle East, “because you won’t need them by the time I’m finished.” He says that American officers would do whatever he ordered them to do, whether within the law or not. “They’re not gonna refuse me. Believe me.” And he promises to seize Middle Eastern oil, as a kind of war spoil.

Erratic as he has been over the years, he has been consistent on one thing, for sure: admiration of strongmen. Here he is in 1990, giving an interview to Playboy, as the Soviet Union was faltering: “Russia is out of control, and the leadership knows it. That’s my problem with Gorbachev. Not a firm enough hand.” His interviewer said, “You mean ‘firm hand’ as in China?” Mr. Trump answered, “When the students poured into Tiananmen Square, the Chinese government almost blew it. Then they were vicious, they were horrible, but they put it down with strength.” America, he said, could use such strength.

Of Vladimir Putin, he is an ardent fan. Last December, an interviewer pointed out that Putin kills his political opponents, invades sovereign countries, etc. Mr. Trump said, “He’s running his country, and at least he’s a leader, you know, unlike what we have in this country.” That was a shot at President Obama, of course. His interviewer persisted: But what about the killing of political opponents? Mr. Trump replied, “Well, I think our country does plenty of killing also.”

That is what conservatives have long decried as a false “moral equivalence.”

Mr. Trump has taken a strong stand against intervention and what he and others characterize as “nation building.” He charges that George W. Bush & Co. lied America and its allies into the Iraq War. He also says that President Bush should have been impeached. Saddam Hussein’s crimes, he minimizes. Here he is at one of his rallies: “Saddam Hussein throws a little gas. Everyone goes crazy. ‘Oh, he’s using gas!’”

He also defends Saddam Hussein as a great foe of terror. “Do you know what he did well? He killed terrorists. He did that so good. They didn’t read ’em the rights. They didn’t talk. They were a terrorist, it was over!” In point of fact, Saddam Hussein was a great harborer and funder of terrorists. Under his wing were Abu Nidal and Abu Abbas, among many others.

An interesting moment came when Mr. Trump was asked about Recep Tayyip Erdogan, and his vicious crackdown in Turkey after a recent coup attempt. Mr. Trump said that America had to focus on its own problems. “When the world looks at how bad the United States is, and then we go and talk about civil liberties, I don’t think we’re a very good messenger.”

Let’s stipulate that candidates usually cannot be held responsible for the endorsements they receive. But Mr. Trump’s fans around the world are an eyebrow-raising bunch. They include Viktor Orbán in Hungary. (Fine.) The Le Pens in France (all three of them). Robert Mugabe in Zimbabwe. Mr. Putin in Russia. And Kim Jong Un in North Korea.

Why should Kim Jong Un be warm to Mr. Trump? Because the Republican nominee has questioned America’s alliance with South Korea. He has also questioned its alliance with Japan, all of which makes East Asian democracies nervous.

The Baltic states, among others, have reason to be nervous as well. Mr. Trump has said that he would come to their aid only if they had paid their dues, as NATO members. The Estonian president, ­Toomas Hendrik, was quick to say that his country, for one, was all paid up.

Almost never does either Mr. Trump or Mrs. Clinton talk about freedom, democracy, or human rights. These things are thought to have a “neoconservative” smell. What do you do if you’re a conservative in the Reagan-­Thatcher mold, and an American voter? This November, there is precious little to choose from