Fighting terrorism, war or police actions?

George Bush's administration has put its terrorism prevention hopes on fighting wars overseas, as we all know too well!  We invaded Afghanistan because the government there harbored OBL and the masterminds of the 9-11 plot.  We invaded Iraq probably to avenge Bush's dad, maybe for oil, and least likely but somewhat probable to prevent nuclear weapons acquisition by Saddam.  Meanwhile, it is doubtful that we have done enough in the policing area to discover and prevent another terrorist attack, either homegrown terrorist or international terrorist, on or should I say in the homeland (God I hate that phrase).  I think using a bit of imagination and logic will make my point here that war alone is not the best way to deal with terrorism, and Bush may well find himself without anyone to attack in the future.

Let us imagine that a bomb, even a nuclear bomb, goes off in the near future in a cargo container sitting on a dock of a US port.  Great devastation happens, but the authorities have no idea where the actual bomb was housed in all the damage or who put it there.  What do the readers here think we/America/Bush would do, and what would happen to George Bush and his administration?  As an additional question, what IS the best way to prevent such a horrible scenario from happening?