BRUSSELS—A tense NATO summit and President Donald Trump’s scheduled meeting Monday with Russian President Vladimir Putin are fueling uncertainty about the U.S.’s commitment to defending Europe and reinforcing the view that the region needs to provide for its own security.
European leaders at this week’s meeting of the North Atlantic Treaty Organization pledged to raise military spending after Mr. Trump hinted that failure to share more of the financial burden of defending the region could prompt the U.S. to go its own way.
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