Don't measure Russian wheat with your bushel.
Per the bolded part: credible with whom?
Whose opinion does Vlad Putin give a flying fart about?
Credible with the rest of the G8 (save China) perhaps. I don't think even Putin can keep up his spoilt teenager routine for ever.
Putin may be, as Max Hastings described him, "Stalin's spiritual heir", but even Stalin chose not to intervene in the Greek Civil War and did not invade Yugoslavia when it broke from Moscow.