The bombing attack in Manchester, England, that killed 22 people and injured dozens more occurred outside an arena where people were leaving after a concert.Venues where a large number of people gather can have security as people are entering an arena, but just outside as they are leaving poses another challenge.The attack has alerted all of Europe as to the threats from terrorist suicide bombers, especially where a large number of people gather, or are leaving a secured building, or arena. It is nearly impossible to have a defense against what happened in Manchester.Terrorists are finding ways to target areas with fewer defenses, The Wall Street Journal reported.Officials are saying it is clear that the suspect who exploded the bomb is part of a terrorist network. How many of these networks are there and where will the next strike be? The United States is not safe from a strike.However, with each attack security becomes tighter.After an attack such as the one in Manchester, fear is created. That’s one of the goals of terrorists. The attack in England will lead to greater security, but nothing that will be 100 percent safe. It just can’t be done unless all freedom of movement is curtailed.