In 1777, when Britain received words of the drubbing its forces had suffered at Saratoga to the American rebels, a friend of Adam Smith’s exclaimed that “the nation was ruined”. The wise philosopher calmly replied: “There is a great deal of ruin in a nation.”

That proposition is about to be put to the test by President-elect Donald Trump.

Yes, I can barely believe that I am actually writing those words: “President Trump.”

I never thought he was remotely qualified for the highest office, and I never thought he would win. I was obviously wrong about the latter. Now I have to pray that I was wrong about the former.

November 9, 2016, is a dark, depressing day for me and for the slim popular majority of Americans who voted for Hillary Clinton. It is easy on a day such as this to fall prey to one’s worst fears. Is this the dark night of fascism descending on America? Maybe. Is this the triumph of white supremacists? Could be. Is this the end of Nato and the triumph of Vladimir Putin? Quite possibly. I admit that I am deeply worried that these cataclysmic scenarios could actually come to pass. This really could be Apocalypse Now.

But I have to admit it is also possible that the worst will not happen and that Trump will exceed the low-low expectations that greet his ascension. In truth, although I have been warning — along with many others — of the catastrophic consequences of a Trump presidency, I have no idea what he will actually do. No one does, probably including Trump himself. If there is any optimism to be gleaned on this day after, it lies in the very fact that Trump has been so utterly incoherent on just about every policy issue.

On immigration, for example, he began by promising to build a wall that Mexico would pay for and to deport 11 million undocumented immigrants. He ended the campaign by saying that United States taxpayers would build the wall with Mexico eventually paying us back and that deportations would proceed “in a very humane way”, targeting “gang members” and “drug peddlers”.

What about mass deportations? “We’re going to make a decision at a later date.”

He even suggested that he would not rule out a pathway to citizenship for undocumented immigrants.

On homeland security, at first he called for a “total and complete shutdown of Muslims entering the United States”. By the end of the campaign, this radical idea had been dropped. It had “morphed”, he said, “into an extreme vetting from certain areas of the world” — whatever that means.

In the battle against terrorism, he began by calling for taking Iraq’s oil, for bombing the “s**t” out of the areas under Islamic State occupation, for torturing terrorists and killing their relatives — all of which would constitute war crimes. At a March 3 debate, he insisted that the military would carry out his orders even if those orders were illegal under international law; the very next day, however, he reversed himself and said he would not order the armed forces to do anything illegal. By the end of the campaign, he was saying that “after taking office, I will ask my generals to present to me a plan within 30 days to defeat and destroy Isis. This will require military warfare but also cyberwarfare, financial warfare and ideological warfare”.

In other words, the anti-Isis plan is “to be determined”.

On abortion, he used to describe himself as “very pro-choice”. During the campaign, he became so anti-abortion that he called for women who get the procedure to be punished, before walking back that position. Now he says he is in favour of overturning Roe v Wade and letting the states decide, which would effectively mean that abortion would remain legal in almost every state.

On American troops overseas, he has called Nato “obsolete”, but also said he wants it to play a bigger role in the war on terrorism. He has said that if US allies do not “pay up” for the protection provided by American troops, he would withdraw them, but he has also said this is only a bargaining position and implied that he does not really mean it. He has said he didn’t care if South Korea and Japan acquired nuclear capabilities after the withdrawal of US forces, but subsequently denied saying that.

What are we to make of all this? My conclusion is that Trump has few fixed principles beyond self-promotion. He wants to make America “great”, but has little idea how. He has expressed certain sentiments — in favour of being strong and surprising our enemies, against political correctness, immigration and disadvantageous trade treaties — without knowing exactly how they would translate into policy.

During the campaign, I thought this was a tremendous weakness because Clinton had policy knowledge and specifics that he lacked, but in office it could be a saving grace. If Trump were to staff his administration with competent professionals with prior government experience, and if he were to listen to their advice, he could actually wind up implementing a fairly conventional conservative agenda in many respects. He could be especially positive in economic policy, where he has promised to cut taxes and regulations — a promise that, if not offset by job-killing tariffs, could turbocharge growth.

Granted, the Trump we saw on the campaign trail was so erratic that it is hard to believe he will be disciplined and prudent in office. But I am hoping against hope that he will grow in the White House — that the office will make the man. Because if that doesn’t occur, the consequences are too ghastly to contemplate.

•Max Boot is an author, consultant, editorialist, lecturer, military historian, and now the Jeane J. Kirkpatrick Senior Fellow in National Security Studies at the Council on Foreign Relations