I think that Trudeau made a very calculated decision here. He knows full well that there in around 150 preconditions that have to be met before construction even begins! 

Mathematically, what are the odds that all of the preconditions will even be met! Then, you have to deal with all the court challenges and with the native population.

NO....It was easy for Trudeau to make this decision because he knows full well that this pipeline will NOT be built.