Given Canada's priorities and the high probability that it will never come close to paying 2%, it doesn't belong in NATO.  As was mentioned here repeatedly, the 4 or 6 plane commitment in the middle east recently didn't make much of a difference. 
The hair brained scheme of looking for a war to participate in has supposedly been held up because Canada is waiting for the U.S. to tell it what to do (LOL) as has been reported here.
Canada should withdraw from NATO,  and form a new defense treaty with the U.S., where much of  Canada's  defense will be acknowledged to be provided by the U.S.  Then, to counter Russia in the arctic,with a presence now that seems insurmountable, Canada should concentrate on its coastline and the arctic, with the U.S. providing support in the Arctic.

Canada will never be able to pay 2%.