In this war someone can be on the front lines whether he is on a bus in Tavistock Square or on a U.S. Army helicopter in Jalalabad. Unfortunately, there are limits to how much can be done to protect the home front, which is why it is preferable to try to kill terrorists and sap them of their ideological energy overseas. Commercial aviation appears pretty well locked down in the West — or so one hopes — but mass transit, with its multitude of access points and its countless fast-moving passengers, is impossible to secure in a similar fashion.
Americans can take some cold comfort in the fact that al Qaeda surely would prefer to hit here in the States, but seemingly can't manage it. Such an attack, of course, could take place tomorrow. But that it hasn't yet is probably some testament to the efficacy of the Patriot Act, the immediate detention of hundreds of Muslim immigration violators after 9/11 (most, no doubt, innocent of any evil intention, but perhaps a crucial handful not), and tighter border control in general. Britain passed a new Prevention of Terrorism Bill only in March and, like most European countries, has relatively lax immigration and asylum policies.
Of course, all of these antiterror initiatives in the U.S. have been criticized by the ACLU and the usual suspects on the left. What they don't acknowledge is what we've been reminded of yet again — it's a war.