When then-President John F. Kennedy used Navy vessels to blockade Cuba in 1963, he made it clear they were to prevent Soviet ships from delivering missiles to the island nation. U.S. officials were in contact with Moscow, explaining how such interceptions would work.

Are similar lines of communication open between Washington and Iran?

U.S. Navy vessels including an aircraft carrier were on station or headed there Monday afternoon – to stop Iranian ships carrying arms to Houthi rebels in Yemen. Plans were to intercept and, presumably, board and search any Iranian craft entering the quickly established blockade zone.

Of course, the United States and other powers should be doing more to thwart Iranian armed intervention in other countries. That should have been occurring months ago.

But now that President Barack Obama has decided finally to act decisively, is he using diplomatic initiatives along with match his military commitment?

Let us hope so. One of the great fears in 1963 was that Moscow might react violently if the U.S. Navy stopped and boarded a Soviet ship. Close contact between the two powers was intended to avoid that.

Similar safeguards are even more critical now for various reasons. One is that the modern blockade is occurring not in our nation’s backyard, but Iran’s.