RE: Euro under attackCAD much the same; likely, in that case, organized out of Ottawa to support the (inefficient) manufacturing base of Ontario. As soon as the CAD tries to go up from par, the brakes are put on and it reverses below par.
I don't know exactly what/how is "spent" to accomplish it all. Maybe Canadian central bank has stocked up on USD(?).
In the end, it highlights the great defender of the USD; it is the mere fact that so much of the world economy relies on the US penchant for consumption.