We have apparently been tracking these people for some time.
My thought is that the Royal Navy, perhaps the Royal Australian Navy, and ourselves have been passively tracking these vessels with JSTARS aircraft and attack submarines.
If these guys are flying the Jolly Roger, so to speak, you want to vaporize them as quickly as possible if they have WMD charges on them.
Be Seeing You,
Chris
JSTARs are not designed to track ships, although I suppose they have some capability in that area. The vehicle of choice would be the P-3 Orion, with the Texas Instruments, now Raytheon, APS-137 surface search (and ISAR) radar. We've got a lot more of those in any event. Many friendly nations, including Australia, Canada, Norway, Spain, Portugal, Chile, South Korea, Greece, Argentina , Japan and the Netherlands, have various versions of the P-3. Pakistan has some too. See http://home.wxs.nl/~p3orion/index.html The only "problem" with the P-3s is that their primary anti-ship weapon, the Harpoon, might be a bit on the puny side for a really big ship, like a 400 footer.