Not so long ago, Europeans believed that despite Donald Trump’s harsh words, Washington would never endanger its Cold War alliances. “Do not read his tweets, follow his actions,” senior American officials told their European colleagues when the conversation turned to the future of the trans-Atlantic relations.

How wrong we were to believe them. It was the tweets that really mattered in the end.

Within hours of the religiously anticipated NATO summit in Brussels today, President Trump was castigating Germany, historically one of America’s closest allies, claiming, ridiculously, that it is “captive” to Russia and calling NATO countries “delinquent.”

Clearly, Mr. Trump is ignoring European Council President Donald Tusk’s appeal: “Dear America, appreciate your allies. After all, you don’t have that many.”