Mr Trump proposes to create an autarkic society: to build physical walls and tariff barriers.  In 1776 The United States separated from England because it wanted  English tariffs against it to be dropped. That decision  was probably correct although south western  Ontario was populated by Empire loyalists who disagreed. Now again international  trade and tariffs are being used by a US leader  to  win domestic political battles. This time  it really isn't quite such a good idea.  Mr Trump's  ideas about trade self-sufficiency will be vigorously debated especially by US/Canada border states  which rely as much as we do upon the NAFTA. However  Ottawa should take  the Wall and the Tariff comments in this Trump Towers press conference  as a warning shot across our bows and  secure more trade deals with other countries. Perhaps the  Indian trade agreement which was about to be signed in the Harper Government would be something to look at.