BERLIN (Reuters) - Late last month, Chancellor Angela Merkel’s top foreign policy adviser was asked what a Donald Trump presidency would mean for Germany and offered a rather hopeful assessment.

U.S. President-elect Donald Trump speaks at a "Thank You USA" tour rally in Grand Rapids, Michigan, U.S. December 9, 2016. REUTERS/Mike Segar

The realities of the presidency would force Trump to change his tone, Christoph Heusgen told an audience in Berlin. Trump had German roots. And he was considering former critics such as Mitt Romney, a more centrist Republican, for top cabinet posts in a sign that he would be inclusive.

“This is reassuring,” Heusgen said.

Two weeks later, the hopes in major European capitals that Trump would shift into “presidential mode”, distance himself from the controversial stances of his campaign and bring a diverse group of outsiders into his administration are fading and a new anxiety is taking hold.

Government officials say recent decisions - from the appointment of a climate change sceptic to run the Environmental Protection Agency, to Trump’s clash with China over Taiwan and his appointment of several Goldman Sachs bankers to top positions - suggest he could be far more disruptive to European interests than initially assumed.

And so, after the shock of the U.S. election and a period of wishful reflection on how Trump might change, a shaken Europe is bracing for confrontations with Washington on a range of issues, from Russia and the Iran nuclear deal, to free trade, climate change and even European integration.

“It is becoming clearer by the day that this is not going to be about an evolving set of consistent policies but rather the opposite,” said a senior western European diplomat, who visited Washington recently to assess the mood.

“It is all about being disruptive. No one knows where and how he will choose to be disruptive. But we are coming around to the view that this is who Trump is, and that it’s part of his strategy.”

DRAWN OUT SPECTACLE

A little over a month since the U.S. vote, European officials are still struggling to understand exactly what Trump will do when he enters the White House next month, beyond the expectation that he focuses chiefly on domestic priorities.

The confusion is partly because filling out Trump’s cabinet has become such a drawn-out process, with candidates such as Romney being paraded into the president-elect’s New York base at Trump Tower and praised by him on Twitter, only to be jettisoned or forgotten days later as new contenders emerge.

The most important appointment for many foreign capitals was finalised on Tuesday, with the CEO of oil giant Exxon, Rex Tillerson, named secretary of state over pretenders like Romney, former New York Mayor Rudy Giuliani and retired general David Petraeus.

Tillerson elicited a range of reactions, with some European officials expressing concerns about his close ties to Russia and President Vladimir Putin, and others reassured that the head of a major corporation with international experience would become America’s top diplomat.

“Optically, it’s not good at all,” said a senior eastern European diplomat whose country looks to the United States and NATO to protect it from Moscow’s regional ambitions. “But the thought of a U.S. secretary of state who actually knows Russia is intriguing.”

Trump’s overtures towards Russia have deeply worried Merkel’s entourage. The German chancellor has led the European Union’s tough response to Russia’s annexation of Crimea and its role in eastern Ukraine, moving in lockstep with President Barack Obama in punishing Moscow with international sanctions.

Should Trump decide to ditch the U.S. sanctions, German officials acknowledge that the European consensus would crumble, leaving Merkel’s Russia policy in tatters and Ukraine yet more vulnerable.

But there is also growing anxiety about the nuclear deal between western powers and Iran, especially after the appointment of leading Tehran critic Michael Flynn as Trump’s national security adviser.

Because the Iran deal is an international agreement backed by the United Nations Security Council, it will be more difficult for Trump to withdraw from it unilaterally; other powers could also refuse to follow suit if he did.

The concern in Europe is that Trump could stick to the deal but ratchet up sanctions in non-nuclear areas, a move that could produce a tit-for-tat response from Tehran that might ultimately doom the nuclear pact.

“If we see tension increase with Iran, it will be a test for the snapback mechanism,” said a French official, referring to a tool that allows sanctions to be reinstated if Tehran is found to be violating the terms of the agreement.

REVOLUTIONARY EVENT

The list of transatlantic flashpoints goes far beyond Russia and Iran. Trump’s stance on Israeli settlements on the West Bank, financial deregulation, China, trade and climate change are all concerns for Europe.

His decision to take a phone call from the president of Taiwan, calling into question nearly four decades of American “one China” policy, was an early sign that he will flout diplomatic protocol and tradition.

Volker Perthes, head of the German Institute for International and Security Affairs in Berlin, says Trump’s copious use of Twitter is also worrying European governments, many of whom assumed this would stop after the election.

“Will Merkel have to be woken up at 3 a.m. because Trump sends a tweet saying Putin told him the Russia sanctions were stupid?” said Perthes. “You can’t rule this out.”

Some see the potential for an even deeper rift over elections in the Netherlands, France and Germany next year, and possibly in Italy and Britain in 2017.

Trump was quick to applaud Britain’s vote to leave the EU in June. He has also cozied up to leading Brexiteer Nigel Farage, raising questions about how he might behave in the forthcoming campaigns - such as the French presidential election where far-right National Front leader Marine Le Pen is expected to perform strongly on a eurosceptic platform.

The senior western European diplomat said governments would be closely watching whether Steve Bannon, the former head of right-wing website Breitbart News, would try to spread populist conspiracy theories across the Atlantic from his new perch as a senior strategist in the Trump White House.

Breitbart has announced plans to expand into Germany and France in anticipation of the elections.”The Europeans are in a state of shock,” said Charles Grant, director of the Centre for European Reform, who was in Washington last week with Perthes to discuss a Trump presidency with U.S. officials.

“If Trump were to support Marine Le Pen like he supported Farage that would be a revolutionary event in transatlantic relations,” he said. “If you’re supporting someone who wants to destroy the euro, the EU and the western liberal order and who is a friend of Russia, then you’re not just setting back transatlantic relations, you’re destroying them.”