Greg Sheridan’s article “Great leaders knew immigration truth: populate or perish” from Saturday’s Weekend Australian assails “the decisive turn by conservatives and some of their icons against a substantial immigration program”. “Destroying our immigration program”, he says, “would be a step … to national suicide”. These are serious charges, and Sheridan is a serious journalist (his riotously funny book, “When We Were Young and Foolish”, notwithstanding), with whose foreign affairs and defence views I almost invariably concur.