In the unknown future of U.S. national-security challenges, safe still beats sorry -- especially when those challenges already appear daunting.

With the number of Secret Service members and agents caught up in the partying-with-prostitutes scandal in Cartagena now at a dozen, and six already gone, how much wider and deeper does this go?

After his fourth-place showing in Florida, Ron Paul, by then in Nevada, told supporters he had been advised by friends that he would do better if only he dumped his foreign policy views, which have been derided as isolationism.