Republican presidential nominee Donald Trump told the American Legion National Convention in Cincinnati, Ohio, on Sept. 1 that if he is elected he would be “uncompromising” in defense of U.S., end the “era of nation-building” and craft foreign policy focused on destroying radical Islamic terrorism. (Ty Wright/Bloomberg)

The foreign-policy establishment remains overwhelmingly opposed to Donald Trump’s bid for the White House, unifying around Hillary Clinton as the only responsible option despite ideological differences — support that has been brought into sharper focus in the week since North Korea defiantly launched its fifth nuclear test.

As Kim Jong Un’s authoritarian regime remains belligerently committed to developing intercontinental ballistic missiles, several international security experts warn that the next president will probably face the culmination of those efforts. And they worry that Trump is ill equipped to navigate the complicated geopolitical forces at play.

Eliot Cohen, an active anti-Trump voice, said that he has never seen foreign-policy professionals so stridently hostile to a candidate.

“He is not only an ignoramus, but he’s a dangerous ignoramus who doesn’t know the first thing about foreign policy and doesn’t care and has some very dangerous instincts,” Cohen, who served in the George W. Bush administration, told The Washington Post in a recent interview. “Part of what is so dangerous about him is not just his ignorance and contempt for our alliances, but his failure to understand how important these have been to our security since 1945. And he has already done a lot of damage. Our allies are deeply shaken by this election.”

On the campaign trail, Trump has regularly signaled that he would consider pulling American support away from traditional allies — naming Japan and South Korea in particular — and out of mutual-defense alliances such as NATO. He has insisted that NATO members are not paying their fair share for American protection. On several occasions, he also has floated the idea that Japan should perhaps develop its own nuclear deterrents to deal with threats in the region.

Republican presidential candidate Donald Trump criticized Democratic rival Hillary Clinton's foreign policy leadership during the Values Voter Summit on Sept. 9, saying she led to the "massive failure" in North Korea and Iran. (The Washington Post)

Those suggestions, which were widely panned, fly in the face of a consensus on American defense and nonproliferation dating back to World War II.

Despite the deep skepticism about their candidate, the Trump campaign has sought to undermine Clinton’s experience as secretary of state, pinning diplomatic failures in North Korea on her policies. Trump’s campaign said Friday that North Korea’s latest nuclear test is a referendum on Clinton’s diplomatic efforts as secretary of state, which he said was full of “catastrophic failures.” In a statement, spokesman Jason Miller said that the North Korean nuclear program grew in sophistication under her watch.

Trump himself blasted Clinton on the stump: “Just today it was announced that North Korea performed its fifth nuclear test, its fourth since Hillary Clinton became secretary of state. It’s just one more massive failure from a failed secretary of state. She’s failed at everything,” Trump said during a campaign event in Washington. “Her policies have also put Iran onto a path of nuclear weapons. And I have to say, made them, overnight, an absolute power. They were dying three years ago.”

That accusation is part of a broader effort by the Republican Party to turn Clinton’s strength and expertise on foreign policy against her — aided by a drumbeat of controversy over her improper use of a private email server during her tenure at the State Department.

Trump also has blasted her judgment for supporting interventions in Iraq and Libya, despite advocating similar views at the time.

While political strategists have fought over whose administration is to blame over North Korea’s continued march toward intercontinental nuclear capabilities — the first nuclear test was launched during the Bush administration — foreign policy experts have been more measured in their assessments.

In conversations with The Post, several said that suggesting there’s a singular person to blame for the North Korean nuclear problem ignores the complicated geopolitical realities making the situation almost unworkable.

“We’re worried about our own interest and protecting our own interests, having to worry about protecting the interests of our allies, and it can’t be seen as undercutting our allies,” said Toby Dalton, co-director of the Carnegie Endowment for International Peace. “All of these relationships are nested in ways that make it very difficult to come to the table with clear objectives that are agreed on, and to work in a process that somehow satisfies all of the interests.”

The Clinton campaign has, meanwhile, used the situation in North Korea to urge voters to think carefully about who they want making high-stakes foreign-policy decisions. Clinton’s messaging has been overt in suggesting that she is uniquely positioned to manage a diplomatic resolution amid likely escalation of the stakes — and that Trump is simply unqualified.

“This is another reminder that America must elect a president who can confront the threats we face with steadiness and strength. . . . And we need a president committed to reducing — not increasing — the number of nuclear weapons and nuclear states in the world,” Clinton said, in a clear reference to Trump. “More countries with nuclear weapons in Northeast Asia would increase the chances of the unthinkable happening. We cannot take the risk.”

In several interviews, Clinton said that she believes the situation in North Korea has reached a turning point. She has called on the United States to strengthen its security alliances with South Korea and Japan — which she called “critical to our missile defense system” — even while insisting that China will need to play a role and escalate its pressure on North Korea.

“I think we have an opening here that we haven’t had for the last seven years that I intend to do everything I can to take advantage of,” she said.

The Trump campaign has not delivered such policy prescriptions, though Trump said in January that he would force China to take ownership of the situation. But he has also spoken in favorable terms of the North Korean dictator — to the great discomfort of many, even within his own party.

“If you look at North Korea, this guy, I mean, he’s like a maniac, okay? And you’ve got to give him credit,” Trump said in January during a campaign event. “He goes in, he takes over, and he’s the boss. It’s incredible. He wiped out the uncle. He wiped out this one, that one.”

Trump’s campaign and surrogates have remained committed to blaming Clinton. In a statement released by the Trump campaign, retired Maj. Gen. Bert Mizusawa suggested that Clinton and Obama have been too weak in handling nuclear talks with North Korea and Iran: “Clinton’s failed policies allowed threats to us and our allies to thrive around the world, including emboldening Iran and North Korea to accelerate their development of nuclear capabilities with impunity.”

But outside the campaign, even those who have been critical of Obama — including Cohen — have been mindful to look at the events in their totality.

“The Obama administration really hasn’t done anything about it. Three of the five nuclear tests have been under their watch, but I can’t say that any other administration were able to slow them down in any way,” Cohen said. “And that’s what it’s going to come down to, are you going to consider under certain circumstances direct action, or are you just going to have to live with it?”