Trump's campaign slogan "Make America Great Again" is "about the restoration of supposedly good old times," but it has real effects on other nations, Gabriel told the Berlin Foreign Policy Forum. The gathering was held in advance of a NATO foreign ministers meeting that begins Tuesday in Brussels and includes Secretary of State Rex Tillerson.
"We see a return to borders and the supposed strength of the nation-state," Gabriel said.
He cited Trump's announcement that the United States will withdraw from the Paris climate accord, his undermining of the international nuclear deal with Iran, sanctions on Russia approved by Congress that could harm Germany's energy supplies and the potential U.S. designation of Jerusalem as the "undivided" capital of Israel.
Those foreign policy moves were made without much consideration of European views, Gabriel said.
If the Iran deal collapses, the risk of war and insecurity rises for Europe, he warned.
On Jerusalem, he underscored Germany's view — shared by the United States for decades — that the status of the city can be resolved only through negotiations between Israel and the Palestinians, who claim East Jerusalem as the capital of a future state.
"Anything that aggravates the crisis is counterproductive," Gabriel said.
U.S. relations with Germany have soured under Trump, who has described Chancellor Angela Merkel's handling of migrants and refugees as a "catastrophic mistake" and has accused the country of failing to pay back "dues" to NATO. He has also strongly criticized Germany's trade imbalance with the United States.
Speaking in German, Gabriel said that Germany should adopt a tougher and more self-reliant stance that does not necessarily rely on U.S. leadership.
"Germany cannot afford to wait for decisions in Washington or to just react. We have to describe our own positions and, if necessary, also make clear to our allies where the limits of our solidarity are reached."
The foreign minister's pessimism was mirrored in public opinion polling data released at the conference by the Körber Foundation, a German think tank. Among Germans, 56 percent said the country's current relationship with the United States is somewhat or very bad, while 88 percent said Germany's defense partnership with European nations should have priority over future partnership with the United States.
The survey of 1,005 respondents was conducted Oct. 4-18 and had a margin of error of five percentage points.
Gabriel, who met with Tillerson in Washington on Iran and other issues last week, said Germany and other nations should continue to find ways to influence U.S. policy.
Trump and his advisers have set out a view that "the world is no longer a global community but an arena and also a battleground in which nations, nonstate actors and companies fight over advantages," Gabriel said.
In that arena, a country "has one and then the other as partner if that serves their own interests," he said.
He warned that Germany should not accept "a submission to U.S. politics like we have never previously seen."
Trump campaigned on promises to pull the United States out of international trade deals and other compacts he called an infringement on U.S. sovereignty. He is deeply skeptical of international organizations and of the underlying premise that the United States has a disproportionate duty to lead or fund them.
But Gabriel said a reordered relationship between Europe and the United States was underway before Trump.
One reason, he said, is that demographic changes in the United States will soon mean that a majority of Americans have roots in Latin America, Asia and Africa rather than in Europe.