Good article in the post by R. Jeffrey Smith and Peter Finn on how recent cases show that it’s harder to pull off secret assassinations these days. Notable examples include the Russians and Alexander Litvinenko, the Isrealis and Mahmoud al-Mabhouh, and the U.S. and the kidnapping of a Muslim Cleric in Italy. Obviously, the Predator drone strikes show that overt assassinations are still all the rage but that’s not really a big surprise.
I don’t think this really holds when talking about intra-country assassinations, in those cases suspicions will always be there but no investigation would be allowed. Similarly if the nation of the killing is willing to participate in a cover-up then the secret is likely to stay one.
On the whole, I do think this is a real positive for international relations. I still have mixed feelings about the use of targeting killings in Pakistan, but they seem to be both effective and comparatively low casualty. The implicit support and explicit condemnation from Pakistan seems like a risky situation, but is hardly unheard of and may be more tenable after the Taliban have exposed their own brutality.
However, use of assassination outside of war may take out bad guys with key knowledge or connections but on the whole seems more useful for killing political leaders and dissident threats. On the whole, when people want to hide violent acts from the eyes of the world, it isn’t typically to further world peace.