An apology offered and, equally important, received is a step towards reconciliation and, sometimes, recompense. Without that process, hurts can rankle and fester and erupt into their own hatreds and wrongdoings.

Climate change respects no borders.

War is a crucial, deeply ingrained part of human history. It has to be understood.

There was that argument that if we had more women in positions of authority, the world would be a nicer place. And then we got Golda Meir, Margaret Thatcher, Sirimavo Bandaranaike, Indira Gandhi. When women become acclimatised to war, they can become every bit as ruthless as men.

Theodore Roosevelt's policy to build a two-ocean navy confirmed that the old-style isolationism of the founders had not survived the modern, increasingly globalized world.

If we don't take responsibility for each other, it seems to me the future is going to be even bleaker.