This is an archived article that was published on sltrib.com in 2017, and information in the article may be outdated. It is provided only for personal research purposes and may not be reprinted.

President Trump has performed a service of sorts to our debate over how the United States views itself and its role in the world. He has reminded the democratic left and the democratic right — note the small "d" — that they share more common ground than they often realize about the importance of democracy, the gifts of modernity, and the value of pluralism.

Trump has done this by articulating, fitfully and inconsistently, a dark worldview rooted in nationalism, authoritarianism, discomfort with ethnic and religious differences, and a skepticism about the modern project. He did this again during a European visit that was disconcerting both for what Trump said and for the isolation of the United States within the very "West" whose cause the president claims to champion.

His lack of constancy makes it difficult to judge exactly what he believes. We commonly describe his contradictions as the product of administration power struggles between Steve Bannon and Stephen Miller, the populist nationalists, and James Mattis and H.R. McMaster, the representatives of a more conventional approach to foreign policy.

On the days when Trump pledges allegiance to NATO and our allies, we see Defense Secretary Mattis and national security adviser McMaster as winning. When Trump veers off this course by dissing allies and going rhetorically apocalyptic, we declare senior White House aides Bannon and Miller triumphant.

Optimists about Trump insist that "the grown-ups," as Mattis and McMaster are often somewhat obnoxiously described by old foreign policy hands, will eventually limit the damage the president can cause us. The last several days should push them toward reappraising their hopefulness.

Trump's European trip, including his meeting with Vladimir Putin, was always going to be a high-wire act, given the president's unpredictability and his allergy to briefing books. For Trump, everything is personal, which means he's subject to being easily played. Foreign leaders know that flattering him is the way to his heart — the Chinese and Saudis seemed to have understood this well — and that his deepest commitments appear to be to his business interests.

But to the extent that Trump does have a gut instinct about the world, it seems closer to Bannon's. The president's spontaneous outbursts, his Twitter revelations, and his reactions to individual foreign leaders point Bannon's way.

Trump has spoken with far greater affection for Putin, Saudi princes and the right-wing nationalists now in power in Poland than for democratic pluralists such as Germany's Angela Merkel and France's Emmanuel Macron. At the G-20 summit, in fact, both Merkel and Macron sounded more like post-World War II American presidents than Trump did.

And the ambiguity about what Trump said during his two-hour meeting with Putin about Russian meddling in the 2016 election (the administration denied that Trump had accepted Putin's denials, as Russia claimed, but its own account of what Trump actually did tell him was hardly reassuring) only underscored the president's reluctance to confront the Russian leader on anything. "Trump gave Putin exactly what he wanted" was the headline on a commentary in the New York Times by Russian writer and dissident Masha Gessen. It was hard to deny its truth.

In his speech in Poland on Thursday, Trump did commit himself to the Western alliance, but in an otherwise gloomy, backward-looking and Manichaean address.

"The fundamental question of our time is whether the West has the will to survive," Trump said. "Do we have the desire and the courage to preserve our civilization in the face of those who would subvert and destroy it?" If we fail to defend what our "ancestors" passed down to us, Trump warned, "it will never, ever exist again."

To which one might respond: Yikes! Trump's words were remarkably similar to Bannon's pronouncements in a speech to a traditionalist Catholic group in Rome in 2014. Bannon spoke of a "Judeo-Christian West" that finds itself "in a crisis" and confronts a "new barbarity" that "will completely eradicate everything that we've been bequeathed over the last 2,000, 2,500 years."

This dire view should remind the democratic left and the democratic right that while they have disagreed on many aspects of American foreign policy over the last two decades, they share some deep allegiances. These include a largely positive assessment of what the modern world has achieved; a hopeful vision of what could lie before us; a commitment to democratic norms as the basis of our thinking about the kind of world we seek; and a belief that ethnic and religious pluralism are to be celebrated, not feared.

They also see alliances with fellow democracies as serving us better than pacts with autocratic regimes that cynically tout their devotion to "traditional values" as cover for old-fashioned repression and expansionism.

Democrats have many incentives for opposing Trump. But it's Republicans who have the power that comes from controlling Congress. Their willingness to stand up to a president of their own party could determine the future of democracy and pluralism. He is, alas, a man whose commitment to these values we have reason to doubt, and his European jaunt did nothing to calm those fears.

Twitter: @EJDionne