But, even in the voluminous catalogue of world leaders who have engaged in ego-wilting acts of Trump sycophantism, this ...

Trump is welcomed by NATO Secretary General Jens Stoltenberg as he arrives at the summit on Wednesday. Stoltenberg, left, sits across from Trump at a breakfast meeting ahead of the summit.

Then it's easier to stop them," he said. "Then daddy has to sometimes use strong language," Rutte, who succeeded Jens Stoltenberg as NATO's Secretary General in October, added.