"Putin today is at a crossroads. The day Putin vowed he would waste Chechen rebels in the outhouse, the course was set for people to be dealt with through arbitrary reprisals, to neutralize and kill opponents. He can step back from this course and find the killers, wherever they are -- abroad, here or in the secret services of a third country. If he doesn't, then this stain will remain with him. He will run the serious risk of persecution wherever he goes. He will become an international pariah. Such a president could bring so much harm to his country because he will either take his country on a path of confrontation or will make too many compromises and become weak. This poisoning is very serious. It looks like the world's first example of nuclear terrorism. If you need just one-billionth of a gram to poison one person, then it does not take very much more to poison an entire country. A very dangerous precedent has been set."

-- Alexei Kondaurov, a Communist State Duma deputy and former KGB general who worked as an adviser to now-jailed Yukos founder Mikhail Khodorkovsky, in the Moscow Times.