"A Significant Thorn"

From the April 10, 2013 Idaho Statesman:

TORONTO — Alberta's premier says if the Obama administration rejects the Keystone XL pipeline it be would be a significant thorn in Canadian-U.S. relations.

It would be a significant thorn in Obama-U.S. relations, too.  Assuming many Americans find out about it.

Read more here: http://www.idahostatesman.com/2013/04/10/2528576/alberta-premier-rejection-would.html#storylink=cpy