Who could have been responsible for the bomb blasts in three Madrid railway stations that killed over 170innocent civilians? ETA, the Basque separatist organisation, or the International Islamic Front (IIF) formedby Osama bin Laden in 1998 and presently co-ordinated by the Lashkar-e-Toiba (LET) of Pakistan? The LET has sleeper cells in the UK, which could operate anywhere in Europe.