Lasting legacy
The 1967 war made Israel into an occupier, which is why more than anything else it matters. The experience has been a disaster for Israelis and Palestinians. Israel built settlements for Jews, in defiance of international law that says occupiers cannot settle their people on the land they capture. Israel, though, sees it differently.
Abba Eban predicted that Palestinians would not lose their "taste for flags, honour, pride and independence."
Military occupation is by definition oppressive. The occupation has created a culture of violence that cheapens life and brutalises the people who impose and enforce the occupation and those who fight it.
Peace negotiations started in the early 1990s to try to unwind the consequences of the 1967 war. Yitzhak Rabin, by then prime minister, shook hands with his old enemy Yasser Arafat under the gaze of a beaming President Clinton on the lawn of the White House in 1993.
The peace process was flawed from the start for both sides. But it was all they had. Extreme Israeli right-wingers took it seriously; they believed it threatened their dream of controlling all the land that God had given to the Jewish people.
A Jewish extremist assassinated Rabin in Tel Aviv in 1995. His killer was so pleased that he had killed a man he saw as a traitor and a threat to Jews that during his first interrogation he picked up a cup to toast his success.
Rabin was the necessary man for Israelis; they trusted him with their security. That was why he was killed.
The peace process might have failed with Rabin. But without the man who had prepared and led the army to victory in 1967, and with Palestinian violence against Israelis rising in the unstable years after the assassination, peace did not have a chance.
Fifty years on from 1967, President Trump - like many new American presidents - is hoping to help Israelis and Palestinians make peace.
If his dreams become substantive talks, they will have to be about the future of the land that was captured in six days of war. It was an extraordinary human drama, which swept up a generation of Israelis and Arabs whose children and grandchildren still cannot live peacefully in the world the war created.
The Holy Land, with Jerusalem at its heart, is a place where the great tectonic plates of religion, culture and nationalism come together. The fault lines that run between them are never quiet and always dangerous. Ignoring the legacy of 1967 is not an option.