The battle over the operation of the multi-national Enbridge Line 5 pipeline appears to have no end. American anti-energy activists—invigorated by their victory in shutting down the Keystone XL pipeline from Canada—have set their sights on Line 5 and won’t quit until the line is shut down one way or another. Cross-border pipelines could soon be a thing of the past, and Canada’s energy security is vulnerable due to this.

Line 5 carries Canadian petroleum products. It begins in Superior, Wisconsin, crosses Michigan, and terminates in Sarnia, Ontario, where the products are refined. It has been safely operating for over 65 years and it services energy needs in the Northeastern United States and Canada with over half a million barrels a day of petrochemicals. If the line were to be suddenly shut down, it would wreak economic havoc. Ideologically driven opponents to the line don’t care about the consequences, though, and they may have their way soon.