Donald Trump's visit to Europe over the past week was phenomenal, to say the least. The U.S. president not only ridiculed the German chancellor before the annual NATO summit in Brussels and avoided anti-Trump demonstrations in London but even infuriated European allies by his meeting with Russian President Vladimir Putin in Helsinki.

The mainstream media in the United States and Europe seemed to be very critical of Trump's arrogance in Belgium, his rudeness in the United Kingdom and his missed opportunity in Finland. Political pundits lamented that it was extremely dangerous for a U.S. president with no diplomatic experience to hastily seek a one-on-one meeting with Putin.

As early as in the summer of 2015 in Washington, a friend of mine who, of course, is a Democrat, told me that Trump may have been suffering from a narcissistic personality disorder. According to him, a diagnostic manual indicates that a person with NPD usually displays some or all of the following symptoms: