a country led by a weak, elderly president unwilling to bear the burden of leading a superpower, and apparently unaware of the disaster he was unleashing on millions of afghans who had relied on america to help them. we'll go back to afghanistan later in this programme. but the whole affair seemed to show that there'd been a major power shift in the world. and surely this belief in america's weakness must have played a part in vladimir putin's thinking as he took the huge gamble of invading ukraine. but now, well, president biden�*s riding high again. it's true, he still gets people's names wrong, his latest victim was president macron of france, but he doesn't look weak any more. and the democrats victory in the state of georgia has just given him another boost. i asked our north america editor, sara smith, for her thoughts.