It's being billed as a halftime summit. And as world governments gather at the United Nations this week, the scoreboard at the half looks ugly. The current UN General Assembly marks the midway point in a 15-year pledge to meet a series of human-development targets by 2030. There's no doubt humanity took its lumps in the first half. Since countries set out 169 targets in 17 areas under the Sustainable Development Goals (SDG) in 2015, the results are uninspiring: 15 per cent are on track to succeed, 48 per cent are moderately or severely off track, and 37 per cent…