Are the ICC right to postpone the Champions Trophy?

The International Cricket Council (ICC) has postponed the ICC Champions Trophy due to be held in Pakistan next month because of security concerns and fears of suicide bombings.

With South Africa having already pulled out of the eight-nation tournament scheduled from Sept 12-28 and England, Australia and New Zealand expressing their concerns over security issues, is the game's governing body right to respond to their fears by postponing the tournament? Is it fair on the Pakistan Cricket Board to deny them their chance to host the event?