In the first two weeks of the Joe Biden presidency, through the medium of Thursday’s powerful speech, sweeping executive orders, a raft of phone calls to leaders on every continent, and an astonishingly, at time exhaustingly regular, series of press conferences, the first outlines of a Biden foreign and defense policy have begun to emerge. It is as total a reversal of the policies of his predecessor as are Biden’s economic, Covid-19 and broad domestic agendas.