As they look at the state of their coronavirus-hit economies and U.S. President Donald Trump’s poor standing in opinion polls, many European leaders may be tempted to put on hold any plans to meet NATO’s target of spending 2 percent of gross domestic product on defense. But Europeans need to wake up. Trump is not a reliable ally, and the damage he has done to the trans-Atlantic partnership is likely to linger.

Trump’s hostility to NATO has been obvious since he called into question its Article 5 mutual defense guarantee during his last presidential campaign. We now know, according to former national security adviser John Bolton’s tell-all memoir, that Trump was ready to pull the U.S. out of NATO at its 2018 summit.

In recent weeks Trump announced without warning that the U.S. will withdraw 9,500 — more than one quarter — of the 34,500 troops it has stationed in Germany because the German government is not spending enough on defense. Then at a Washington press conference with Polish President Andrzej Duda, Trump said a large number of NATO countries were “delinquent” and declared that Europe was taking “tremendous advantage of the United States on trade.”

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