National security

Analysis: Orlando Exposes Key National Security Vulnerability

Every continent has its own unique strategic vulnerability. For Europe, it's the large pockets of Muslim immigrants who feel ostracized and ghettoized in neighborhoods like Saint Denis outside Paris or Molenbeek in Brussels. Europe is also far closer to the ISIS killing fields in Syria, meaning recruits have been able to travel easily to gain battlefield experience.

There is also no effective central European intelligence or security body keeping track of the databases and watch lists. The situation for Europe was made even worse last year when border security across the continent collapsed under an unprecedented wave of mass migration.

Compared to Europe, the United States is far more secure. Relatively few Americans — about 250, according to the Justice Department — have tried to or succeeded at joining ISIS, compared to Europe's thousands. The United States is also far away from Syria, a deterrent to travel.