1917 - Balfour Declaration

Here is the authoritative Wikipedia page that describes the Balfour Declaration:

The gist of Einat's perspective is as follows:

The Balfour Declaration was a tentative promise / declaration of intent
It was the follow up by Zionists that made the difference, and the declaration itself was almost meaningless on its own
The British Empire actually started reneging on promises, and they did so at the worst timing possible for Jews