The only persuasive position I heard during the Bill C-51 debates was in relation, say, to weapons proliferation, weapons of mass destruction. Those sorts of matters could fall outside the scope of the threat to the security of Canada definition within the CSIS Act, so you would want to have a slightly broader definition to encompass those sorts of issues.
You could come up with something that's not as sweeping as the present definition in proposed section 2 that would address those sorts of bona fide concerns.