It is not for a lack of trying. They have been trying to kill Vladimir Putin for sometime now. Even if they succeed, do they think the Russians are going to wimp out and fear the US? Another Russian leader like Medvedev will take his place. Russia has upgraded all its heavy weaponry, fighter jets, attack helicopters, tanks, missiles, rockets, etc. and ready for full scale war with NATO if they enter Ukraine. Also, their factories working 24/7 non-stop manufacturing missiles, rockets, artillery shells. Did anyone see Putin's jet escorted by 6 SU-35 fighter jets loaded with missiles and rockets, armed to the teeth and the state reception by Dubai? Russians love their country. Compare it to the US were there are numerous traitors selling the US out to other countries for a couple of millions. Hell, these idiots are more focused prosecuting Trump on bogus charges just so, he cannot run for President of the United States.