"The senator from Kentucky," said John McCain, speaking of his colleague Rand Paul, "is working for Vladimir Putin … and I do not say that lightly."

What did Sen. Paul do to deserve being called a hireling of Vladimir Putin?

He declined to support McCain's call for a unanimous Senate vote to bring Montenegro into NATO as the 29th member of a Cold War alliance President Trump has called "obsolete."

Bordered by Croatia, Bosnia-Herzegovina, Serbia, Kosovo and Albania, tiny Montenegro has a population roughly that of D.C., and sits on the western coast of the most volatile peninsula in Europe.

What strategic benefit would accrue from having Montenegro as an ally that would justify the risk of our having to go to war should some neighbor breach Montenegro's borders?

Historically, the Balkans have been an incubator of war. In the 19th century, Otto van Bismarck predicted that when the Great War came, it would come out of "some damn fool thing in the Balkans." And so it did when the Austrian archduke was assassinated in Sarajevo June 28, 1914, by Serbian ethnonationalist Gavrilo Princip.