Should the US dump NATO? And would a Republican president ever consider it? According to Donald Trump, the answer to both is potentially yes, at least in terms of its leadership. Trump also told the Washington Post that the US should pull back on its security commitments in the Pacific, too:

Donald Trump outlined an unabashedly noninterventionist approach to world affairs Monday, telling The Washington Post’s editorial board that he questions the need for the North Atlantic Treaty Organization, which has formed the backbone of Western security policies since the Cold War.

The meeting at The Post covered a range of issues, including media libel laws, violence at his rallies, climate change, NATO and the U.S. presence in Asia. …

Trump said that U.S. involvement in NATO may need to be significantly diminished in the coming years, breaking with nearly seven decades of consensus in Washington. “We certainly can’t afford to do this anymore,” Trump said, adding later, “NATO is costing us a fortune, and yes, we’re protecting Europe with NATO, but we’re spending a lot of money.”

Trump sounded a similar note in discussing the U.S. presence in the Pacific. He questioned the value of massive military investments in Asia and wondered aloud whether the United States still was capable of being an effective peacekeeping force there.

The US has played a dominant role in world leadership in both the Atlantic and Pacific theaters since World War II. Abandoning NATO, or at least its leadership, would reduce our influence almost immeasurably. Why should America give up its leadership role in world affairs? Trump points to its cost:

“I do think it’s a different world today, and I don’t think we should be nation-building anymore,” Trump said. “I think it’s proven not to work, and we have a different country than we did then. We have $19 trillion in debt. We’re sitting, probably, on a bubble. And it’s a bubble that if it breaks, it’s going to be very nasty. I just think we have to rebuild our country.”

He added: “I watched as we built schools in Iraq and they’re blown up. We build another one, we get blown up. We rebuild it three times and yet we can’t build a school in Brooklyn. We have no money for education because we can’t build in our own country. At what point do you say, ‘Hey, we have to take care of ourselves?’ So, I know the outer world exists and I’ll be very cognizant of that. But at the same time, our country is disintegrating, large sections of it, especially the inner cities.”

The major driver of national debt isn’t defense spending, not even in the NATO sense. In a budget of $3.9 trillion, defense spending amounts to $585 billion, or 15% of overall federal spending. That’s not to say that the national debt has no impact on how we should calculate our foreign policy, but the national debt mostly comes from domestic spending, especially on entitlements, and the interest we’re paying on the debt already accrued. And Trump has made it clear that serious entitlement reform is off the table.

Ted Cruz responded later in the day by claiming that Trump’s professed foreign policy of retreat and leading from behind sounds awfully familiar, and questioned Trump’s depth when it came to the example he cited — Ukraine:

“Trump’s policy idea [on NATO] is entirely consistent with Obama withdrawing from Europe,” Cruz said in a televised town hall on CNN, and would give Russian President Vladimir Putin “a foreign policy victory.” …

Cruz, however, said that Trump’s remarks were “really quite astonishing,” speculating that Trump is ignorant of the United States’ diplomatic relations with Ukraine. Once the third-largest nuclear power in the world, Ukraine agreed to give up its nuclear weapons in return for an assurance that the U.S. would help protect its sovereignty.

“I bet you dollars to donuts Donald Trump has no idea about that,” Cruz said. Given the United States’ lack of leadership there, what other country would ever voluntarily give up its nuclear weapons now, Cruz asked rhetorically. He tied Trump’s suggestion to President Obama’s foreign policy approach.

“Trump’s foreign policy is the Obama-Hillary ‘leading from behind'” strategy, he said.

Trump’s foreign policy sounds familiar in other ways as well. It resembles the foreign policy stances of Ron Paul, who made a career of distrusting foreign entanglements and pushed an unabashedly isolationist foreign policy. Given that Rand Paul was supposed to inherit the keys to Ron’s constituency and push the GOP in a more libertarian direction, this shift has plenty of irony — but should not be discounted for its political power, either. The GOP has a long history of isolationists within its coalition who have had to sit on the sidelines for decades of Cold War interventionism, and now another generation of Middle East action as well. Just as Trump has motivated the white blue-collar segment of the Republican Party that has been frustrated with economic stagnation, Trump could well generate even more enthusiasm among the party’s isolationists, who have long argued that the US should go back to its historical studied neutrality and focus mainly on trading relationships.

If so, however, then Cruz is right — Trump will take us further on the path which Obama and Hillary Clinton put the US over the last eight years. And once we concede that leadership position, we may find it difficult to regain when necessary … and we’ll still be sinking ever deeper into debt.

Addendum: The timing on this could not have been worse, Hugh Hewitt argues:

Attack on NATO from @realDonaldTrump worst timed major policy shift proposal ever? https://t.co/xJiGGBBMOZ

— Hugh Hewitt (@hughhewitt) March 22, 2016

To be fair, this interview took place before the attacks in Brussels. But it’s not as though those attacks came out of the blue, either.

Update: Fixed a grammatical issue in one paragraph.