Donald Trump’s formal foreign policy address last week hurled a stick into the hive of the foreign policy establishment. Republican and Democrat foreign policy mavens erupted and buzzed around to attack the intruder. Anyone not reading the text would think it was a contradictory spewing of nonsense, another in the long line of Trump outrages. In fact, the reaction to the speech was far more revealing than Trump’s address itself.

The Clinton campaign brought out former secretary of state Madeleine Albright and Sen. Tim Kaine (D-Va.) to respond. Albright, a supporter of Bush’s Iraqi debacle and promoter of America as an “indispensable nation,” scornfully announced that she was “hoping for something that made sense.” Kaine termed Trump’s use of the words “America First” disqualifying. Neoconservatives Bill Kristol and Charles Krauthammer damned it for echoing President Obama’s foreign policy. The Post editorial board dismissed Trump’s argument as “loose, frequently contradictory and embedded in a bucket of falsehoods,” suggesting it reflected the “isolationism of Robert A. Taft” and Pat Buchanan’s “fondness for authoritarian regimes.”

Trump’s speech did recycle many of the lies that Republicans routinely tell about Obama’s foreign policy. He accused Obama of apologizing to enemies and alienating friends. He called the Iran nuclear deal a disgrace and wrongly claimed Iran is violating it. He postured that Obama’s failure to enforce the “line in the sand in Syria” was a measure of weakness. He charged Obama with mistreating Israel, gutting missile defense and abandoning Poland and the Czech Republic. Although Trump read from a teleprompter, the prepared speech didn’t cover up the shallowness of his understanding.

But putting aside the partisan lies about Obama, Trump issued a direct and clear hit on the establishment foreign policy consensus that has failed dramatically over the years. Trump argued that after the end of the Cold War, “our foreign policy veered badly off course.” He criticized the “chaos” we’ve created in the Middle East — Iraq, Egypt, Libya, Syria. He indicted the rush to a new Cold War with China and Russia. He condemned our trade policy for running unprecedented deficits and weakening our country. He promises to get out of the “nation-building business.”

Most of all, Trump, after all the bluster, urged surprising sobriety in the use of military force. “War and aggression will not be my first instinct,” he said. “A superpower understands that caution and restraint are signs of strength.” Revealingly, Trump’s establishment critics, virtually without exception, dismiss his views without displaying the slightest awareness of the serial catastrophes wrought by their policies. Kristol concluded that if Trump leads Republicans, there will be “two parties committed to an agenda of national decline.”

Yet, neither Kristol nor his neocon comrades offer any recognition that the policies they have championed rank among the most costly debacles in U.S. history. This blindness to their record of failure renders their critiques risible. Trump’s speech reflects his canny understanding of establishment failure. His alternative — a stronger military that is used less, a balanced trade policy — fits well with the mood of the American people.

Needless to say, however, Trump is not a credible champion for a new policy. He is more interested in insult than in strategy. And he displays only a passing knowledge of the world and of the policies he is talking about.

But what his speech reaffirmed is that we desperately need a real debate about foreign policy. The failed policies of past years — still embraced by the bipartisan foreign policy establishment — need to be challenged by a new realism that has a better grasp of our real security concerns. This new realism would understand the limits of U.S. power and the need to focus seriously on rebuilding an economy of shared prosperity. It would embrace the Pentagon’s realization that catastrophic climate change is already a real and present danger that poses a greater threat than the terrorist bands that capture the headlines. It would learn from the past and be far more skeptical of regime change and the false promise of painless “nation building.” It would understand that the United States cannot afford to police the world and that building and respecting international law is central to our interest. It would seek to engage Russia and China, not gear up for a new Cold War. It would abandon a global economic policy that has been forged by, for and with the global corporations and banks, and formulate an alternative that would better serve America’s working people.

This debate has begun to break out in the faceoff between Sen. Bernie Sanders (I-Vt.) and Hillary Clinton in the Democratic primaries. Clinton champions our current course, while sporting a more interventionist and bellicose policy than that of the president she served as secretary of state. Not surprisingly, neoconservatives and the indispensable-nation crowd alike increasingly embrace her.

Sanders has fitfully begun to challenge the orthodoxies that she represents. He has questioned her record of regime change from Iraq to Libya to Syria. He has been a skeptic of the push for a new Cold War and arms race with Russia. He’s been courageous in speaking common sense about the Middle East, arguing that true security for Israel requires treating the Palestinian people with “respect and dignity.” He has indicted a trade policy that has run unprecedented deficits and undermined wages and security at home.

As Sanders enters the final weeks of the campaign and heads to the Democratic convention, he should grasp this opportunity to develop these themes and outline the elements of a new security agenda. He should expand his challenge to the failed foreign policy of the establishment and add it to his indictment of our corrupted politics and rigged economy. He is helping to energize and educate a new generation coming into American politics. It is imperative that a real security agenda be part of that education.

Clinton is identified with the failed policies of the past years that she has championed. She prides herself on her hawkishness. White House correspondent Mark Landler, author of the new book “Alter Egos” on the Obama-Clinton relationship, reports that Jake Sullivan, Clinton’s leading foreign policy adviser, told him, “There’s no doubt that Hillary Clinton’s more muscular brand of American foreign policy is better matched to 2016 than it was to 2008.”

Clinton and Sullivan are mistaken. Americans are weary of wars without end and without victory. They are increasingly skeptical of trade deals that protect the rights of global corporations while costing the jobs and incomes of American workers. They are looking for a leader who will focus on rebuilding this country from the inside out and the bottom up.

Sanders can demonstrate the power of a new realism in the run-up to the convention. His pressure might help Clinton realize just how out of step her “more muscular brand of American foreign policy” is. She’s already adjusted her stance on trade. Maybe Sanders can move her to revise her scorn for Obama’s sensible caution against doing “stupid stuff.” Trump is not a credible leader for this or any country. But the country will be better-served if the next president trades hawkishness for a new realism.

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