I've written on this topic. I would direct members to the bibliography I provided at the end of the documents I circulated. Under “Book and Book Chapters”, the third entry is “Civil remedies for terrorism”. It's a chapter I wrote precisely on the previous incarnation of terrorism bills, where I spoke strongly against a procedure whereby states would be designated.
I believe it's a politicization of the judicial process. I believe it's unprincipled and should not be adopted as an approach. This is what the United States has done. The U.S. has entered into a very awkward game of designating states and then undesignating them, and using that as a political carrot, so to speak. Recently, for instance, the U.S. government de-designated Libya. I think the Americans regret that right now. This was done months ago before current events had exploded.
This is a cautionary tale of why designating states is the wrong approach, either for terrorism, torture, crimes against humanity or war crimes. These crimes are wrong and are prohibited by the highest norms of international law, no matter who commits them.