As the young Trump administration searches for political accomplishments, it can take credit for one thing in its first 100 days: It has killed consistency.

And by being consistent, we mean: taking seriously what President Trump has said previously — sometimes just hours earlier.

It’s not just that the hyperbolic Trump has failed to do many of the three dozen things he promised to do early in his presidency. Like deporting 2 million criminal undocumented immigrants. (“Day one, my first hour in office, those people are gone!” ) Or repealing Obamacare.

The political problem is that the more Trump backtracks on — or ignores — what he’s said before, the more he damages the populist brand he sold to voters and the trust he should have abroad as the leader of the free world.

Many people voted for Trump because, unlike most career politicians, he sounded like a man who would actually do something about the issues he’d been carping about from the sidelines for years. But there’s a growing disconnect between what candidate Trump stated or promised and what President Trump is delivering.

And his base voters are starting to notice. Trump not only has the worst approval rating of any president at similar points in their terms, he’s also losing support among his core — whites, men and Republicans — according to a recent Quinnipiac Poll.

Maybe they’re losing faith that he’ll do what he said he’d do.

In 2013, Trump tweeted “What will we get for bombing Syria besides more debt and a possible long term conflict? Obama needs Congressional approval.”

Four years later, President Trump bombed Syria — without congressional approval.

What happened to Trump’s earlier position?

“Welcome to the presidency,” former Secretary of Defense and CIA Director Leon Panetta told me the other day as we were discussing the attack on Syria. The former congressman from Monterey has seen how tough decisions are made through his time with the administrations of Bill Clinton and Barack Obama.

“All of this talk about how we could just retreat into the fortress of ‘America first’ and not have to assume responsibility in the world is all fiction,” Panetta said, referring to Trump’s “America first” campaign slogan about not involving the United States in foreign entanglements unless there is a clear threat to the homeland.

“Trump is coming to recognize something President Obama had hoped would happen — that other countries would step up and assume some responsibility — isn’t going to happen,” Panetta said.

Some analysts say “America first” remains a slogan at this point. The problem is that without a coherent, consistent set of international policies, Trump may get the wrong message from the bipartisan support he received after the Syria strike and start firing missiles more regularly, said former State Department counterterrorism expert Daniel Benjamin. A survey by FiveThirtyEight.com found that 79 of 100 senators offered qualified statements of support for the Syria strike.

“He’ll enjoy the approbation he is getting for the strikes, and I worry a little about what that will mean for him,” Benjamin said. “I worry that he’ll think this is a winning suit for him and keep doing it elsewhere without a consistent set of policies to guide him.”

Like in North Korea, for example, which Panetta expects to conduct some sort of nuclear test on Saturday to celebrate the birthday of that country’s founder. So how will Trump react?

During the campaign, candidate Trump suggested that perhaps Japan and South Korea should arm themselves with nuclear weapons as a deterrent to their neighbor’s unpredictability. In a nod to his “America first” slogan, Trump said the U.S. was spending too much protecting nations like Japan and “we can’t afford to do it anymore.”

That hands-off attitude transformed into a hands-on threat Tuesday when Trump tweeted “North Korea is looking for trouble. If China decides to help, that would be great. If not, we will solve the problem without them! U.S.A.”

If the reality of the presidency caused Trump to get tougher on Syria and North Korea, it seems to have caused him to soften on China.

Before he took office, Trump accused China of “raping us” through unfair trade deals and wanting “our people to starve” by taking jobs away from U.S. manufacturers.

Candidate Trump also promised he would designate China a currency manipulator on “day one” of his presidency. On Wednesday, President Trump said that the dollar is strong and that he would no longer brand China a currency manipulator.

That was only one of Trump’s international backtracks Wednesday. The other came when he met with NATO Secretary-General Jens Stoltenberg. During the campaign, Trump called NATO “obsolete.” But on Wednesday Trump said, “I said it was obsolete. It’s no longer obsolete. ... I complained about that a long time ago, and they made a change and now they do fight terrorism.”

Apparently Trump wasn’t paying attention to the fact that NATO countries — his own country included — have been fighting terrorism since long before the Sept. 11 attacks.

There’s nothing wrong with changing a position if the facts on the ground change. But there is a problem when a leader changes his take depending on whom he spoke to last, as seems to have happened with Stoltenberg. The value in keeping your word is it engenders trust in that word.

“We’ve got a president who has never been in government, never done foreign policy, never used force,” Benjamin said. “We’re on a trip without maps here.”

Joe Garofoli is The San Francisco Chronicle’s senior political writer. Email: jgarofoli@sfchronicle.com Twitter: @joegarofoli