This intrigues me for two reasons. First, because, as the the author points out, it gives us a clearer idea of what we are doing with a "War on Terror." It provides a method for defining the crime of terrorism in a way that can garner international support. That would give us more allies in this fight and a way to better deal with countries might not aid us because they agree with the aims of the terrorists. By agreeing that terrorism itself is a threat to all nations, we have a diplomatic lever to use with friends and foes alike.
Secondly, it provides an interesting near-future fiction or role-playing scenario. If terrorists are criminals that can be pursued across jurisdictions by anyone that encounters them, a nation plagued by terrorists could simply set out rewards for the capture of the terrorists. Independent operators, then, could pursue and capture the terrorists. Sort of modern-day letters of mark.