Geography has given the US unrivaled security. Trump is destroying it | Gil Barndollar and Rajan Menon

The US's greatest strategic advantage is its friendly neighbors. But its ties to Canada and Mexico are being undermined

The secret to American power and pre-eminence was best summed up more than a century ago.

America, observed Jean Jules Jusserand, France's ambassador to the United States during the first world war, is blessed among the nations". To the north and south were friendly and militarily weak neighbors; on the east, fish, and the west, fish". The United States was and is both a continental power and, in strategic terms, an island - with all the security those gifts of geography provide. No world power has ever been as fortunate. This unique physical security is the real American exceptionalism.

Gil Barndollar is a non-resident fellow at the Defense Priorities Foundation. Rajan Menon is Spitzer professor emeritus of international relations at the Powell School, City College of New York, and a senior research scholar at the Saltzman Institute at Columbia University.