Crazy, strange and unsteady are a few of the adjectives used as pundits try to work out what a Trump foreign policy might look like, though one Israeli newspaper seems reassured.
Several German commentators admit to being flummoxed by the speech. "It's not very easy to follow him," writes Der Spiegel's Washington correspondent, Veit Medick.
The candidate's comments can "hardly be called a coherent plan", he adds.
Die Welt's Clemens Wergin sees Mr Trump as a security risk, saying his speech confirmed many experts' view that "we are dealing with an unsteady character".
France's business daily Les Echos asks whether the speech is "a return to isolationism", reporting that Mr Trump wants to point the US in "a less interventionist direction".
The speech also makes the front page of the Spanish daily, El Pais.
Washington correspondent Marc Bassets says Mr Trump's foreign policy doctrine could be summed up as a mix of "isolationism, realpolitik and militarism".
Two heavyweight US papers are unimpressed with the speech, with The New York Times headlining its scathing editorial: "Donald Trump's Strange World View."
It argues that he "did not exhibit much grasp of the complexity of the world, understanding of the balance or exercise of power, or even a careful reading of history."
In the Washington Post, Dana Milbank writes about "Trump's crazy attempt not to sound crazy".
"Trump did not offer more detail on how he would 'bring peace to the world,' but he gave strongman promises that everything would be fine", he laments.
"Perhaps the most unnerving promise Trump made was his determination to be erratic", he continues.
"On this vow, Trump has already made good - and that's just the problem."
Nahum Barnea, writing in Israel's Yedioth Ahronoth, says Mr Trump "took his foreign policy inspiration from the Westerns" and calls it "cowboy diplomacy".
Boaz Bismuth has a different view in Yisrael Hayom, calling the speech "firm, focused".
"Trump wants a decent, strong, loyal America, but he is also not a sucker. And he sees in Israel the most loyal ally of the United States," he writes.
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Donald Trump's foreign policy speech on Wednesday leaves a few media commentators scratching their heads.