"Recent, widely-reported incidents in France, Russia, Sweden, and the United Kingdom demonstrate that the Islamic State of Iraq and ash-Sham (ISIS or Da’esh), al-Qa’ida, and their affiliates have the ability to plan and execute terrorist attacks in Europe. While local governments continue counterterrorism operations, the Department nevertheless remains concerned about the potential for future terrorist attacks. U.S. citizens should always be alert to the possibility that terrorist sympathizers or self-radicalized extremists may conduct attacks with little or no warning."
LINK TO US BUREAU OF CONSULAR AFFAIRS
Wars in the Middle east and chaos in Africa are working to goad the radicalised masses into Europe.