This has massive implications for Canada.  The "refugees", wherever they came from, will become refugees en mass at our borders.  Our border with the U.S. is porous and this could result in the sudden appearance of many without any means to provide for themselves.  This could result in the social infrastructures of civic, provincial, and national governance, being overwhelmed logistically and financially.  The social implications are enormous as Canada would face having to deal with refugees not well vetted.  The stress on our health care, social assistance, criminal justice, housing, education, et cetera, would be unfathomable.  Taxation, deficit spending, larger governance, social/cultural conflict, and a stagnant economy, could spell unaffordable disaster.  We also have a PM who has recently stated his government's willingness to accommodate without taking into consideration the full implications.  We will be a Germany without the wealth.  

Trump's action will harm its' best ally.