Sounds like Britain has won WW I singlehandedly. Do I sense a touch of complex of superiority in you, my friend?
And, of all people, it is you who hectors on history?
"and freeing Jerusalem from the Muslims, it set aside certain captured lands (all present-day Israel and Jordan) to be a Jewish homeland. This great gift was later attenuated "
A gift? This is more that elitist. Have you gifted Afghanistan to the Afghans when you left? Or Iraq to the "Iraqis," which never existed before. Look at the maps of your country from 1945 and 2000: have you "gifted" one quarter of the Earth's surface to the respective inhabitants, or did you run home with tail between your legs because your Empire has crumbled. Its people no longer identified with colonial enterprise, and became only slightly less socialist than the Soviets. Why do you single out Palestine as a "gift?" A bit patronizing, isn't it?
It is a pleasure to see a Brit who is proud of his heritage. British colonialism, in particular, has indeed civilized much of the world (compare, for instance, Barbados and Haiti). But your knowledge and view of the Britain's proud history may benefit from further study and analysis, respectively.
When Britain issued the Balfour Declaration it was a major indisputable World power. It was an Empire.
The betrayal of the Jews coincided with the beginning of the decline of the British Empire to the common status it has today. And with its Islamic overrun it will get worse.
One would think British hubris would have declined with their fortunes. I guess not. Give it time.
Haiti was a French colony (that explains a lot).