This comes just after Canada expressed their fear of a "new Iraq or Afghanistan" in Mali to justify not sending troops.
IMHO this (the document + Canada position + that particular discussion) translate the feeling some political deciders may have: after 2 invasions that turned to be half victories at best they are very much affraid to engage their troops in an another military adventure. In that perspective, AQ reached one of its objectives: terrorise governments.

On the other hand, what Bob is saying makes a lot of sens:
There are different levels of drawing in, if the French keep their intervention short and then the West conducts small scale low visibility special operations it will be affordable and ultimately result in their defeat. If we attempt another major stability operation we'll be playing into their game.
But I believe many in the field and at the flag level are aware of that choice.