Democratic presidential candidates detailed their plans for combating ISIS Thursday as the focus of the 2016 campaign shifts to national security and foreign policy in the wake of the terrorist attacks in Paris last week.

Stanford terrorism experts say Islamic State attacks in Paris signal that the terrorist group seeks to expand operations well beyond the borders of Iraq and Syria so it can bring about a global, apocalyptic war with the West.

America's strategy for dealing with ISIS has been predicated on the belief that its ravages can be contained to Iraq and Syria. But attacks on a Russian airliner in Egypt, suicide bombings in Beirut and deadly assaults in Paris demonstrate that premise is wrong.