U.S. officials say they are puzzled at Spain’s reluctance to let FBI experts assist in the Madrid bombings investigation and worry that clues might be missed that could link the attack to others around the world. So far the FBI’s only involvement is a limited one involving examination of fingerprints and assistance in background investigations of the suspects. The bureau has offered to do more but the Spanish have not accepted. Two senior U.S. officials, speaking Thursday on condition of anonymity, said the concern is that the broader war on terror may suffer if the FBI’s expert team is frozen out of the investigation. Full Story