It is basic math that if you increase the population of people from the vicious 'civil war' currently underway in Islam, then you will increase the terror threat. Keep in mind how much money is already spent on preventing attacks at present because of the threat coming from Islam. It is also worth paying attention to trends. And Europe is one step ahead of Canada and the US. And in Europe the biggest killer in attacks is radical Islam as well as the biggest source of civil unrest and crime. How long until that becomes the case in North America? Probably when Muslims make up the same percentage as they do in Europe.