This was an obvious attempt to undermine the policies of the sitting President by informing the Russian Government that Trump would reverse Obama's sanctions. The message was obviously received since Putin did not retaliate against Obama's action, as he normally would have done. In view of Flynn's very close ties with Trump, who heavily relied on him for advice on security matte4rs, it is obvious that Flynn must have been acting with Trump's knowledge and very likely following a direct order from Trump.