The arrest this week of two rural California men, after one acknowledged he attended an Al Qaeda camp in Pakistan to “learn to kill Americans,” has revived questions about the hidden presence of potential terrorists on the home front. To some experts, the arrests in what appears to be a widening investigation in Lodi are a sign that some homeland-security procedures are working as hoped. To others, the news suggests that Al Qaeda still has a dangerous and unknown reach into cities and towns across the US. Full Story