Okay, sir. The threats have evolved in terms that it started with long-range aviation and evolved into ICBMs, and then before 9/11 we were looking at outside. After 9/11, we started looking not only outside the approaches to the continent but also inside, since on that day all the attacks came from within the United States.
In terms of the measures we can take, NORAD is assigned the mission by the Government of Canada and the Government of the United States. What we can do is provide a combined joint assessment of the threats and explain the capabilities and requirements to mitigate those threats. Once we give our ideas, then it's not really up to NORAD itself to decide how to deal with these threats, or to accept or not accept the risks of these threats.
In terms of terrorism, for maritime we have vessels of interest for which, based on the information we collect, we will do an advisory message or a warning message. Then these vessels will be inspected, visited mainly by a law enforcement agency, most of the time, and civilian authorities.
From the air, we are still concerned about the commercial aviation threat. The bin Laden papers, when he was killed, still mentioned a high interest by al Qaeda to use aviation against North America, particularly general aviation as well. The business jet type of aviation could be used as a missile. Since 9/11 we have measures in place where we exercise regularly detecting a potential track of interest, doing an interception, and having conferences where, if required, we would take down those tracks of interest.