I do not believe that the former Cat Stevens, now Yusef Islam, is a direct threat to the United States. I do not believe he and his daughter flew to America on Tuesday to inflict intentional harm upon the nation or its interests, nor was he a threat to the passengers on the plane that was to convey him to Washington.
And obviously, diverting that plane to Maine - as the closest ground once the plane was in the air - was a dramatic, wildly inconvenient gesture that was not specifically necessary to protect the safety of the craft or the nation in general. If Islam was on a goverment no-fly list, this should have been caught before he boarded the plane.
BUT, if in fact the government has good cause to believe that Islam (the former singer, not the religion) has contributed money to Hamas and to blind sheik Omar Abdel-Rahman (who was convicted for the 1993 World Trade Center bombing), then he is in fact a "terror threat" because terror is not possible without funding, and those who fund and thereby enable terror are just as guilty as those who carry out the actual acts.
Do we not hold Osama bin Laden responsible for 9/11? He wasn't flying any of the planes, but he funded, encouraged, and provided the organizational structure necessary and sufficient to enable the atrocities.
If we are serious about fighting and winning the war on terror, then we must treat funders with the same degree of seriousness that we treat the perpetrators of terror themselves, even to the point of diverting a flight from London-to-Washington to Maine in order to enforce a no-fly policy.
In addition to demonstrating that we take the letter of this policy literally, we also are sending a message to those who enable terror that we view their activity with deadly seriousness and will prevent them from darkening our soil with their shadow.