Are employers required to check applicants against a terrorist list prior to hiring them?

Also known as Due Diligence, background check can help you dodge and avoid costly mistakes, and is sometimes part of the filtration process in hiring, however, it can be time consuming and some specific information can be difficult to obtain.  This is all in the case of local hiring

However, if you are hiring a someone from abroad, most countries laws' state that part of the required documents for issuing a work permit is to issue a criminal record for the to-be-hired person.  in the USA they call it  FBI Attestation.

Hope this answer helps.

Yes sure. It is highly required in the circumstances.  Behavioural assessments can reflect also :)

yes off course

Not necessary and it is difficult to find out for an organisation. Maximum we can do is asking them to get good conduct certificate from local police. 

It may be applicable for certain region and situation.

Dear Irina, The security situation worldwide is changing... and therefore it is good to check. But practically it will not be possible to always check for "criminal / religious / political" leanings of an individual. The time delay will kill the recruitment effectiveness. Perhaps you could be careful when candidates from trouble-prone parts of the world are considered for a job offer ... I would currently recommend Pakistan, Egypt, Iraq, just to name a few.

Regards

Krish

screening is necessary  for peoples who re  joining you with good model character