Bush may have acted all friendly like with Putin, but while he was doing it, he withdrew from the ABM treaty, and has since then initiated and attempted to initiate other measures that constitute a threat to Russia's national security. Now, we may like to dismiss Russia's concerns by saying that these measures aren't aimed at them (even though they really are), but Russia has no reason to accept these reassurances, and if the shoe were on the other foot, we most certainly would not accept them.