Thanks, Les.
Yes, high-risk countries tend to have a visa requirement. When a visa application is received, the first thing to happen is that the CIC immigration officer overseas makes an assessment of whether the applicant appears to meet certain indicators that might suggest suspicion of membership in a criminal or terrorist organization, or whether there is any other reason why a person might be excluded from Canada.
Those indicators are developed together with our security partners, led by CBSA. An ongoing working group examines country by country the indicators that apply in that country that might suggest a person needs to undergo closer security screening. This would then become a referral to CBSA. Within the last year, we've updated our country indicators for 16 high-priority countries, and 10 more are on the list for this year.