The terrorist threat to Europe

The US continues to warn that al-Qaida may be planning to attack targets in Europe. The warning seems to be based largely on intelligence about a German-based group of militants. Yesterday, a US missile strike in Pakistan killed eight militants, including four suspected German nationals. And today, French police detained 12 people, suspected of links to Islamist extremism. Lisa Mullins gets an assessment from the BBC’s defense and security correspondent Nick Childs is in London.